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# QNT 275 QNT275

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Tutorial

QNT/275

STATISTICS FOR DECISION MAKING

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https://uopcourses.com/category/qnt-275/
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QNT 275 Week 1 Statistics in Business

Develop a 875-word response that addresses each of the following prompts:

Define statistics with citation and reference.

Contrast quantitative data and qualitative data with citation and reference.

Evaluate tables and charts used to represent quantitative and qualitative data.

Describe the levels of data measurement.

Describe the role of statistics in business decision-making.

Provide at least two business research questions, or problem situations, in which statistics was used or could be used.

Format your assignment consistent with APA guidelines.
Click the Assignment Files tab to submit your assignment.

QNT 275 Week 1 Participation The Role of Statistics in Business Decision-Making

Watch the “The Role of Statistics in Business Decision-Making” video.
Consider the following as you watch:

Describe probability theory.

Explain how sampling theory relates to probability theory.

Differentiate between a population and a sample.

Explain, based on the video, why statistics is important in decision-making.

QNT 275 Week 2 Activity Data Set

Resource: University of Phoenix Material: Data Set
You are the manager in a small town in the lake district of a Midwestern state that enjoys a robust tourist season during the summer months but has only a small population of residents during the off season. The Littletown Café adjusts the levels of staff according to the time of year to coincide with the number of guests, with the tourist season typically starting around Memorial Day each year. One wait staff employee can serve 50 guests. When a bus staff employee is added, the pair can serve 75 guests. At 76 guests, the café adds a second wait staff employee, for a total of 2 waiters and one busser. Analysis of guest numbers can support future decisions about scheduling wait staff, dishwashers, and bus staff for the café.
Review the data in the data set.
Create a 875-word report in which you do the following:

Explain why this is (or is not) a suitable sample of quantitative data for the business scenario.

Evaluate the factors that would affect the validity of the data set.

Evaluate the factors that would affect the reliability of the data set.

Explain the steps you took to arrive at your conclusion about validity and reliability.

Display the data set in a chart

Explain briefly why that chart type was selected

Calculate the measures of central tendency and variability (mean, median, mode, standard deviation) for the data.

Interpret the measures of central tendency and variability. What are three conclusions you can draw based on the data analysis?

Format your assignment consistent with APA guidelines.
Click the Assignment Files tab to submit your assignment.

QNT 275 Week 2 Quiz
Complete the quiz for Week 2.
question1
Which of the following variables is qualitative?
Height
Temperature
Gender
Weight

question2

A recent survey of 200 small firms (annual revenue less than \$10 million) asked whether an increase in the minimum wage would cause the firm to decrease capital spending. Possible responses to the survey question were: “Yes,” “No,” or “Don’t Know.” These data are best classified as ____________.
Nominal Scale
Ratio Scale
Interval Scale
Ordinal Scale

question3

Which of the following represents a population and a sample from that population?
Teachers in a high school and members of the parent teacher group
Residents of Albany, New York, and registered voters in Albany, New York
Freshmen at St. Joseph’s University and basketball players at St. Joseph’s University
Fans at a concert who purchase t-shirts and fans at a concert who purchase soda

question4

Which of the following variables is quantitative?
Religious Affiliation
Gender
Marital Status
Temperature

question5

The accompanying chart shows the numbers of books written by each author in a collection of cookbooks. What type of chart is this?
Bar chart for quantitative data
Frequency histogram for quantitative data
Bar chart for qualitative data
Frequency histogram for qualitative data

question6

In order to summarize qualitative data, a useful tool is a __________.
Frequency Distribution
Line Graph
Histogram
Stem-and-Leaf Diagram

question7

ABC Plumbing wants to understand its customers’ perceptions of the quality of the company’s plumbing service calls. They plan to survey a sample of its customer base. What will ABC need to do to ensure that their data is valid and reliable?
The survey must include items that ask customers about their plumbing experiences, the survey sample must include the first 15 customers off the customer database, and the survey method must be repeatable.
The survey must include items that ask customers to rate the quality of plumbing service calls, the survey sample must represent all parts of the customer population, and the survey method must be repeatable.
The survey must include items that ask customers to rate the appearance of the plumbing store, the survey must include all customers, and the survey method must include setting up a table outside the local dollar store.
The survey must include items that ask customers to rate the friendliness of the receptionist, the survey must include all customers from the north side of the city, and the survey method must appeal to all respondents.

question8

A stem-and-leaf diagram is constructed by separating each value of a data set into two parts. What are these parts?
Stem consisting of the leftmost digits and leaf consisting of the second digit
Stem consisting of the second digit and leaf consisting of the last digit
Stem consisting of the leftmost digits and leaf consisting of the last digit
Stem consisting of the last digit and leaf consisting of the leftmost digits

question9

A population consists of _________________.
a subject of interest in a sample
all items of interest in a statistical problem
all items of interest in a sample
a subject of interest in a statistical problem

QNT 275 Week 2 Participation Obtaining a Suitable Sample

Watch the “Obtaining a Suitable Sample” video.
Consider the following as you watch:

Discuss the difference between convenience and random sampling.

Explain how you can obtain a sample size representative of a population.

Provide three examples.

Explain why a sample is used in place of the population.

QNT 275 Week 2 Participation Measuring Central Tendency and Variability

Watch the “Measuring Central Tendency and Variability” video.
Consider the following as you watch:

Define the three standard measurements of the central tendency and provide example of each.

Explain when you might want to use a median number.

Provide an example.

Define a standard deviation and what a standard deviation shows, provide an example.

QNT 275 Week 2 Participation Statistics Intro: Mean, Median, and Mode

Watch the “Statistics Intro: Mean, Median, and Mode” video.
Consider the following as you watch:

Explain how mean is calculated.

Explain how a median is calculated with an even number list.

Define an array.

Provide an example.

Define a mode.

Identify if you can have more than one modal number in a set of data.

QNT 275 Week 2 Participation Finding the Range and Mid-Range

Watch the “Finding the Range and Mid-Range” video.
Consider the following as you watch:

Define a range and provide two examples.

Calculate a mid-range and provide two examples.

QNT 275 Week 2 Learning Team Collaborative Discussion: Descriptive Statistics

Read Case Study 3.3 in Ch. 3 of Essentials of Business Statistics found on page 98.
Click the Fort Myers Sales Data Set link.
Calculate descriptive statistics:the mean, median, mode, and standard deviation in the two sample periods (January and July).
Discuss one of the following:

Identify what changes occurred in the Fort Myers housing market during the 6-month period.

Explain what conclusions you can draw from the data.

Identify what additional data you might want to understand the housing market better.

Explain what role descriptive statistics play in understanding the housing market.

QNT 275 Week 3 CLO Business Decision-Making Project Part 1

Identify a business problem or opportunity at a company where you work or with which you’re familiar. This will be a business problem that you use for the individual assignments in Weeks 3-5. It should be a problem/opportunity for which gathering and analyzing some type of data would help you understand the problem/opportunity better.
Identify a research variable within the problem/opportunity that could be measured with some type of data collection.
Consider methods for collecting a suitable sample of either qualitative or quantitative data for the variable.
Consider how you will know if the data collection method would be valid and reliable.
Develop a 1,050-word analysis to describe a company, problem, and variable.
Include the following in your submission:

Identify the name and description of the selected company,

Describe the problem at that company,

Identify one research variable from that problem,

Describe the methods you would use for collecting a suitable sample of either qualitative or quantitative data for the variable (Note: do not actually collect any data)

Analyze how you will know if the data collection method would generate valid and reliable data (Note: do not actually collect any data)

Format your assignment consistent with APA guidelines.
Click the Assignment Files tab to submit your assignment.

QNT 275 Week 3 Quiz

Complete the quiz for Week 3

question1

What does it mean when we say that the tails of the normal curve are asymptotic to the x axis?
The tails gets closer and closer to the x axis and eventually touch it.
The tails get closer and closer to the x axis and eventually cross this axis.
The tails get closer and closer to the x axis but never touch it.
The tails get closer and closer to the x axis and eventually become this axis.

question2
You work in marketing for a company that produces work boots. Quality control has sent you a memo detailing the length of time before the boots wear out under heavy use. They find that the boots wear out in an average of 208 days, but the exact amount of time varies, following a normal distribution with a standard deviation of 14 days. For an upcoming ad campaign, you need to know the percent of the pairs that last longer than six months-that is, 180 days. Use the empirical rule to approximate this percent.
95%
2.5%
97.5%
5%

question3

For any normally distributed random variable with mean μ and standard deviation σ, the percent of the observations that fall between  and   is closest to _______.
95%
16%
68%
32%

question4

A continuous random variable has the uniform distribution on the interval [a, b] if its probability density functionf(x) ___________.
is constant for all x between a and b, and 0 otherwise
is bell-shaped between a and b
is symmetric around its mean
asymptotically approaches the x axis when x increases to +∞ or decreases to -∞

question5

Mutually exclusive and collectively exhaustive events _______________.
do not have to contain all outcomes in a sample space and may share common outcomes
contain all outcomes in a sample space and do not share common outcomes.
contain all outcomes in a sample space and may share common outcomes
do not have to contain all outcomes in a sample space but do not share common outcomes

question6

What is probability?
Any value between 0 and 1 is always treated as a probability of an event.
A value between 0 and 1 assigned to an event that measures the likelihood of its occurrence.
A value between 0 and 1 assigned to an event that measures the unlikelihood of its occurrence.
A numerical value assigned to an event that measures the number of its occurrences.

question7

Which of the following can be represented by a continuous random variable?
The number of arrivals to a drive-thru bank window in a four-hour period
The number of defective light bulbs in a sample of 5
The score of a randomly selected student on a five-question multiple-choice quiz
The time of a flight between Chicago and New York

question8

Which of the following is correct?
A continuous random variable has a probability density function but not a cumulative distribution function.
A continuous random variable has a probability density function, and a discrete random variable has a probability mass function.
A discrete random variable has a probability mass function but not a cumulative distribution function.
A continuous random variable has a probability mass function, and a discrete random variable has a probability density function.

question9

Which of the following can be represented by a discrete random variable?
The finishing time of participants in a cross-country meet
The number of obtained spots when rolling a six-sided die
The average outside temperature taken every day for two weeks
The height of college students

question10

The probability that a normal random variable is less than its mean is ____.
Cannot be determined
0.0
1.0
0.5

QNT 275 Week 3 Participation Probability and Conditional Probability in Business Decision

Watch the “Probability and Conditional Probability in Business Decision-Making” video.
Consider the following as you watch:

Define probability.

Provide three examples of probability.

Define conditional probability.

Provide three examples of conditional probability.

Describe what questions you might ask to determine probability of risks when starting your own company.

Provide at least three questions.

QNT 275 Week 3 Learning Team Collaborative Discussion: Probability

Resource: Case Study 5.2 in Chapter 5 of Essentials of Business Statistics
Calculate the requested probabilities for items 1-3.
Discuss your findings for the probabilities.

Identify the smoking trend from 1997-2007.

Explain whether this is a discrete, continuous, or conditional probability.

Recommend steps related to smoking behavior based on this trend.

QNT 275 Week 4 CLO Business Decision Making Project, Part 2

Use the same business problem/opportunity and research variable you wrote about in Week 3.
Remember: do not actually collect any data; think hypothetically.
Develop a 1,050-word report in which you:

Identify the types of descriptive statistics that might be best for summarizing the data, if you were to collect a sample.

Analyze the types of inferential statistics that might be best for analyzing the data, if you were to collect a sample.

Analyze the role probability or trend analysis might play in helping address the business problem.

Analyze the role that linear regression for trend analysis might play in helping address the business problem.

Analyze the role that a time series might play in helping address the business problem.

Format your assignment consistent with APA guidelines.
Click the Assignment Files tab to submit your assignment.

QNT 275 Week 4 Quiz

Complete the quiz for Week 4

question1

For a given set of explanatory variables, in general:
a confidence interval is narrower than a prediction interval.
a confidence interval is wider than a prediction interval.
The width of a confidence interval cannot be determined.
the width of a confidence interval is the same as the width of a prediction interval.

question2

The standard error of the estimate measures:
the variability of the observed y-values around the predicted y-values.
the variability of the predicted y-values around the mean of the observed y-values.
the variability of the values of the sample regression coefficients.
the variability of the explanatory variables.

question3

In a simple linear regression model, if the plots on a scatter diagram lie on a straight line, what is the standard error of the estimate?
+1
-1
Infinity
0

question4

Which of the following variables is not qualitative?
Gender of a person
Religious affiliation
Student’s status (freshman, sophomore, etc.)
Number of dependents claimed on a tax return

question5

Consider the following simple linear regression model:   The response variable is:
β0
x
y
ε

question6

Another name for an explanatory variable is the ___.
descriptive variable
independent variable
inferred variable
dependent variable

question7

Serial correlation is typically observed in:
outliers.
sparse data.
cross-sectional data.
time series data.

question8

Consider the following simple linear regression model:   β0 and β1 are:
the unknown parameters.
the random error terms.
the response variables.
the explanatory variables.

question9

What is the name of the variable that’s used to predict another variable?
Coefficient of Determination
Standard Error of the Estimate
Response
Explanatory

question10

Which of the following violates the assumptions of regression analysis?
The error term has a constant variance.
The error term has a zero mean.
The error term is normally distributed.
The error term is correlated with an explanatory variable.

QNT 275 Week 4 Participation Correlation and Causality

Watch the “Correlation and Causality” video.

Define a correlation and provide an example

Define causality?

Explain if correlation causes causality.

Provide evidence with an example.

QNT 275 Week 4 Participation Using Time Series to Analyze Business Trends

Watch the “Using Time Series to Analyze Business Trends” video.

Identify the four components of time series.

Provide an example of each component and how it might be used in business

Explain if this data becomes obsolete over time.

QNT 275 Week 4 Participation Career Connection Discussion: Forecasting

Discuss the following:

Explain what you have learned throughout this course with probability and how you think that will affect your forecasting decisions in your current or future company.

Predict how you will use probability in your current or future company?

QNT 275 Week 5 CLO Business Decision Making Project, Part 3

Prepare an 11- to 15-slide Microsoft® PowerPoint® presentation for the senior management team based on the business problem or opportunity you described in Weeks 3-4.
Include on the slides what you’d want the audience to see (include appropriate visual aids/layout) and include in the Speaker’s Notes section what you’d say as you present each slide. If any source material is quoted or paraphrased in the presentation, use APA citations and references.
Draw on material you developed in the Weeks 3-4 assignments.
Include the following in your presentation:

Introduction slide

Agenda slide

Describe the organization, with a brief description

Explain the business problem or opportunity

Analyze why the business problem is important

Identify what variable would be best to measure for this problem. Explain why.

Apply data analysis techniques to this problem (tell which techniques should be used: descriptive stats, inferential stats, probability, linear regression, time series). Explain why.

Apply a possible solution to the problem/opportunity, with rationale.

Evaluate how data could be used to measure the implementation of such a solution.

Conclusion

References slide (if any source material is quoted or paraphrased throughout the presentation)

Format your assignment consistent with APA guidelines.
Click the Assignment Files tab to submit your presentation.

QNT 275 Week 5 Final Examination

Click the link to the Final Examination.
Complete the Final Examination.
You are allowed one attempt to complete the exam, which is timed and must be completed in 3 hours. Results are auto graded and sent to your instructor.

***The questions of final exam are totally the same. Just the sequence is different.***
1
The salaries of teachers in a particular school district are normally distributed with a mean of \$50,000 and a standard deviation of \$2,500. Due to budget limitations, it has been decided that the teachers who are in the top 2.5% of the salaries would not get a raise. What is the salary level that divides the teachers into one group that gets a raise and one that doesn’t?
45,100
54,900
-1.96
1.96

2
In the accompanying stem-and-leaf diagram, the values in the stem and leaf portions represent 10s and 1s digits, respectively.

The stem-and-leaf diagram shows that the distribution is ___________.

negatively skewed
symmetric
positively skewed

3
Which of the following is a quantitative variable?
House age
House price
House size
4
Which of the following meets the requirements of a stratified random sample?
A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include six males chosen at random, without regard to age.
A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include six people who volunteer for the sample.
A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include six people chosen at random, without regard to age.
A population contains 10 members under the age of 25 and 20 members over the age of 25. The sample will include two people chosen at random under the age of 25 and four people chosen at random over 25.
5
Which of the following can be represented by a continuous random variable?
The number of typos found on a randomly selected page of this test bank
The average temperature in Tampa, Florida, during the month of July
The number of customers who visit a department store between 10:00 a.m. and 11:00 a.m. on Mondays
The number of students who will get financial assistance in a group of 50 randomly selected students
6
In the sample regression equation   what is   ?
The y-intercept
The predicted value of y, given a specific x value
The value of y when x = 0
The slope of the equation
7
Mutually exclusive events ______________.
do not share common outcomes
contain all possible outcomes
do not contain all possible outcomes
may share common outcomes
8
Which of the following can be represented by a discrete random variable?
The circumference of a randomly generated circle
The average distance achieved in a series of long jumps
The number of defective light bulbs in a sample of five
The time of a flight between Chicago and New York
9
A manager of a fast food restaurant wants to ensure that staff are scheduled with the sufficient hours required to meet customer demands without overspending on labor costs. The manager has daily guest counts, sales data, and staff hours for the prior year. What should the manager do next in order to reach conclusions about scheduling restaurant staff?
Provide the data sets to the restaurant owner for analysis by the owner’s staff.
Schedule staff based on the staffing levels used on the same date the prior year.
Perform descriptive statistics, inferential statistics, and time series analysis.
Create a graph of the data and extend the graph forward in time to set the schedule.

10
A-Plus Dry Cleaners wants to understand its customers’ perceptions of the quality of the company’s customer service. They plan to survey a sample of its customer base. What will A-Plus need to do to ensure that their data is valid and reliable?
The survey must include items that ask customers to rate the appearance of the dry cleaning store, the survey must include all customers, and the survey method must include setting up a table outside the local dollar store.
The survey must include items that ask customers to rate the quality of the company’s customer service, the survey sample must represent all parts of the customer population, and the survey method must be repeatable.
The survey must include items that ask customers to rate the friendliness of the staff, the survey must include all customers from the north side of the city, and the survey method must appeal to all respondents.
The survey must include items that ask customers about their dry cleaning experiences, the survey sample must include the first 15 customers off the customer database, and the survey method must be repeatable.
11
The two branches of the study of statistics are generally referred to as ___________.
differential and descriptive statistics
inferential and differential statistics
descriptive and referential statistics
descriptive and inferential statistics
12
Serial correlation is typically observed in:
time series data
outliers
sparse data
cross-sectional data
13
The manager of a retail shoe store has applied statistics to analyze sales, purchasing, and  data and reached the conclusion that the store could reduce costs by reducing inventory of very small and very large sizes, and substituting an online ordering service to drop-ship rare sizes directly from suppliers. How should the manager communicate those results to the store owner?
Summarize the recommendations, supported by visual representation of the data and statistics.
Schedule a conference call with the owner and suppliers to discuss online ordering options.
Project the future online sales data using a line graph.
Provide the complete data set and all statistical analyses to the owner in spreadsheets.
14
Professors at a local university earn an average salary of \$80,000 with a standard deviation of \$6,000. The salary distribution is approximately bell-shaped. What can be said about the percentage of salaries that are at least \$74,000?
15
Which of the following violates the assumptions of regression analysis?
The error term has a constant variance.
The error term is uncorrelated with an explanatory variable.
The error term has a zero mean.
The error term does not have the normal distribution.
16
The study of statistics can be defined as:
the language of data.
the art and science of getting information from data.
the study of collecting, analyzing, presenting, and interpreting data.
17
What is the name of the variable that’s used to predict another variable?
Coefficient of determination
Response
Explanatory
Standard error of the estimate
18
Consider a population with data values of 12, 8, 28, 22, 12, 30, 14.
The median is:
12
22
14
18
19
Which scales of data measurement are associated with quantitative data?
Nominal and ordinal
Ordinal and interval
Ratio and nominal
Interval and ratio
20
What is (are) the most widely used measure(s) of dispersion?
Covariance and the correlation coefficient
Interquartile range
Variance and standard deviation
Range
21
Frequency distributions may be used to describe which of the following types of data?
Nominal and interval data only
Nominal, ordinal, and interval data only
Nominal and ordinal data only
Nominal, ordinal, interval, and ratio data
22
A company wants to estimate the mean price of oil over the past 10 years. What kind of data does the company need?
Descriptive statistics
Cross-sectional data
Time series data
Inferential statistics
23

What type of relationship is indicated in the scatterplot?
A negative linear relationship
A positive linear or curvilinear relationship
A negative curvilinear relationship
No relationship
24
Which of the following is most influenced by outliers?
75th percentile
Mean
Mode
Median
25
Bias can occur in sampling. Bias refers to _____________________.
the division of the population into overlapping groups
the creation of strata, which are proportional to the stratum’s size
the use of cluster sampling instead of stratified random sampling
the tendency of a sample statistic to systematically over-or underestimate a population parameter
26
The owner of a company has recently decided to raise the salary of one employee, who was already making the highest salary, by 20%. Which of the following is(are) expected to be affected by this raise?
Median only
Mean, median, and mode
Mean and median only
Mean only
27
The estimation of which of the following requires sampling?
The Cleveland Indians’ hitting percentage in 2010
The average SAT score of incoming freshmen at a university
U.S. unemployment rate
Total rainfall in Phoenix, Arizona, in 2010
28
Horizontal bar charts are constructed by placing:
each interval of values on the vertical axis and the appropriate range of values on the horizontal axis.
each category on the horizontal axis and the appropriate range of values on the vertical axis.
each category on the vertical axis and the appropriate range of values on the horizontal axis.
29
A hedge fund returns on average 26% per year with a standard deviation of 12%. Using the empirical rule, approximate the probability the fund returns over 50% next year.
0.5%
1%
5%
2.5%

QNT 275 Week 5 Participation Managing the Data Deluge

Watch the “Managing the Data Deluge” video.

Define a data management plan?

Provide an example of good data and an example of bad data.

Explain the following: Other than collecting primary data where might you search for secondary data?

QNT 275 Week 5 Participation Instinct, Debate, and Data Make the Best Decisions

Watch the “Instinct, Debate, and Data Make the Best Decisions” video.

Identify how to make the best decisions,

Provide an example.

Explain whether data the only element used in decision making.

Justify whether instinct should play a role in decision-making.

QNT 275 Week 5 Participation Interpret and Communicate Data Analysis Results

Watch the “Interpret and Communicate Data Analysis Results” video.

Describe how data can be interpreted differently.

Explain how and why data is scrubbed.

Describe three different ways to communicate data.