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Failure to include the null and alternative hypothesis when conclusions are drawn on rejecting or failing to reject the null hypothesis will result in zero (0) points for the problem.

The manager of a Mid-First Bank branch recorded the amount of time each customer spent waiting in line during peak business hours one Monday. The frequency table below summarizes the results.

Waiting time

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FOR MORE CLASSES VISIT

Failure to include the null and alternative hypothesis when conclusions are drawn on rejecting or failing to reject the null hypothesis will result in zero (0) points for the problem.

The manager of a Mid-First Bank branch recorded the amount of time each customer spent waiting in line during peak business hours one Monday. The frequency table below summarizes the results.

Waiting time

(minutes) 0-3 4-7 8-11 12-15 16-19 20-23 24-27

# of customers 14 09 11 06 07 03 02

If we randomly select one of the customers represented in the table, what is the probability that the waiting time will be at least 12 minutes or between 8 and 15 minutes?

The future United State lottery will involve the random selection of six (6) different numbers between 1 and 22. If you select one six number combination, what is the probability that your single lottery ticket will win the lottery?

How many 5-digit numbers can be formed using the digits 1, 2, 3, 4, 5, 6 and 7 if repetition of the digits is not allowed? For example, there can not be 2 7’s.

Determine whether the following is a probability distribution. If not, identify the requirement that is not met.

X 0 1 2 3 4 5

P(x) 0.243 0.167 0.213 0.149 0.232 0.164

The OKC Police Department reports that the probabilities that 0, 1, 2, 3 and 4 car thefts will be reported in any given day are 0.091, 0.218, 0.261, 0.209 and 0.125, respectively. Determine if this is a probability distribution. If not, identify the requirement that is not satisfied.

A Mid-First Bank loan officer rates applicants for credit. The ratings are normally distributed with a mean of 200 and a standard deviation of 50. Find the P60.

Of 139 adults who reside in Norman, Oklahoma selected, 30 of them smoke. Construct a 99% confidence interval for the true percentage of all adults who reside in Norman that smoke.

GE advertises that the average life for its low energy light bulbs is 900 hours. A random sample of 15 of these light bulbs resulted in the following lives in hours.

995 590 510 539 739 917 571 555 916 728 664 693 708 887 849

At the 10% significance level, do the data provide evidence that the mean life for GE’s light bulbs differs from the advertised mean?

Test the claim that the mean lifetime for a Dodge Hemi engine is greater than 220,000 miles. Sample data are summarized as n = 23, sample mean = 226, 450 miles and s = 11,500 miles. Use a significance level of 0.01.

Is there a predicted relationship between the costs of advertising (in thousands of $$$) and the number of products sold (in thousands)?

Cost 9 2 3 4 2 5 9 10

Number 85 52 55 68 67 86 83 73

A company manager wishes to test a union leader’s claim that absences occur on different week days with the same frequency. To test her claim at the 0.05 significance level she collected the following sample data.

Day Monday Tuesday Wednesday Thursday Friday

Absences 37 15 12 23 43

Do the data support her claim?

Data is just data and it is what one does with it that is important. What is grammatically incorrect in the previous sentence?

Responses to a CNN poll to a survey questionnaire are broken down according to employment status and the sample results are shown below. At the 0.10 significance level, test the claim that the response to the questionnaire and employment status is independent.

Yes No Undecided

Employed 30 15 5

Unemployed 20 25 10

Consumer Reports wants to determine if the average lifetimes of ballpoint pins of three different types are the same. The magazine takes a random sample of pens of each type. Results are shown in the following table.

Brand 1 Brand 2 Brand 3

260 181 238

218 240 257

184 162 241

219 218 213

At the 0.05 level of significance is Consumer Reports correct?

The regression equation for a collection of paired data consists of the number of years that students have studied Spanish and their scores on a Spanish language proficiency test if Score = 31.55 + 10.90 Years. Assuming a significant linear correlation between years of study and the test score, what is the single value that best predicts the test score of an individual who studies 4.5 years?

Four pairs of data yield r = 0.942 and the regression equation y ̂=3x. Also, y ̅=12.75. What is the best predicted value of y for x = 2.5?

Write the null and alternative hypotheses for the following claims? Do not use shorthand nomenclature if you want credit for this problem.

The Penske team claims the engine of its racing car has greater fuel efficiency as the Honda engine.

Health care coverage is independent of gender.

The average August temperature in Norman is not more than the average August temperature in New York City.

The higher a student’s athletic ability the lower the score on a math CLEP test.

Hypothetically the weekly salaries of teachers in Oklahoma are normally distributed with a mean of $490 and a standard deviation of $35. What is the probability that a randomly selected teacher earns more than $525 a week?

A study of the amount of time it takes a mechanic to rebuild the transmission for a 1992 Chevrolet cavalier shows that the mean is 8.4 hours with a standard deviation of 1.8 hours. If 40 mechanics are randomly selected find the probability that their mean rebuild time is less than 7.6 hours.

Suppose that you perform a hypothesis test regarding a population mean and that the evidence does not warrant rejection of the null hypothesis. When formulating the conclusions to the test, why is the phrase “fail to reject the null hypothesis” more accurate that the phrase “accept the null hypothesis”?