This is an introductory lesson on statistics. Statistics is the branch of mathematics that involve the data. It looks at how the data is collected, analyzed, and interpreted. The word statistics can also refer to the pieces of information themself, the pieces of data.
If you've ever heard someone talk about a football player's stats, they're talking about how fast he can run, how many catches he makes on average per game. Those pieces of information are pieces of data. And you can also use the words statistics when describing it. The word stats there is short for statistics.
Now, a statistical study analyzes appropriately collected data. When you're analyzing statistics, you're doing statistical analysis. Statistical analysis is all the different ways of collecting, interpreting, and examining data. Now, the subject of statistics has two different branches. The first branch is referred to as descriptive statistics. The second branch is inferential statistics.
Descriptive statistics describes your data. It provides a summary of the information that you've found. Now, the summary can be provided either numerically or visually. A numerical summary would involve pieces of information, like the count, the average, the maximum, and the minimum.
You'll learn many other ways that you can numerically summarize your data, but these are some you might already be familiar with. If you're visually summarizing your data, you'd be looking at charts, graphs, and plots.
The other branch of statistics, inferential statistics, uses the data to draw conclusions. Now, those conclusions can be in the form of estimates or hypotheses. I'll run through an example using these new vocab words.
If we were doing a statistical study on the cost of nonfat milk, we'd want to make sure that we appropriately collected and analyzed our data. So the data we would collect, the pieces of information, would be the prices of milk in a variety of different stores. Now, once we've collected that information, we can use descriptive statistics to describe and summarize the information we found.
We can do this numerically. We can say that we went to 10 stores, that the average was $2.35, that the minimum was $2.09, and that the maximum was $2.57. Or we can do this visually. We can look at a bar graph of all the different prices.
Now, if instead we were doing inferential statistics, we'd want to be making an estimate about a larger group based on a small sample that we collected. So you could say based on the data from 10 stores, I would estimate that the state average price of milk would be between $2.26 and $2.44. This has been your introductory lesson on statistics.