# AP Statistics Curriculum 2007 EDA Statistics

### From Socr

## Contents |

## General Advance-Placement (AP) Statistics Curriculum - Statistics

### Definitions

Variables can be summarized using statistics.

- A
**statistic**is a numerical measure (or a function) that describes a characteristic of the*sample*. - A
**parameter**is a numerical measure that describes a characteristic of the*population*.

We use statistics to estimate parameters.

- We use
**sample-statistics**to estimate/understand**population parameters**or characteristics!

### Example

Suppose we are interested in the meancalory or mean sodium content of hot dogs. It would be difficult to obtain measures of calory and salt content for ALL hot-dogs. However, we can use the Hot dogs datafile that we discussed uearlier. This data contains a sample of 54 major hot dog brands. Some of the interesting **population papameters** are the mean-calory, mean-sodium, variance-of-calory between hot-dogs and variance-of-sodium between hot-dogs. These measures may be estimated from the sample using the corresponding **sample-statistics** (sample-averages and sample-variances).

- Using SOCR Charts and the Charts activities you can produce a number of interesting graphical summaries for this hotdogs dataset.

- The histogram of the
**Calory**content of all hotdogs in shown in the image below. Note the clear separation of the calories into 3 distinct sub-populations. Could this be related to the type of meat in the hotdogs?

- The histogram of the
**Sodium**content of all hotdogs in shown in the image below. What patterns in this histogram can you identify? Try to explain!

### References

- SOCR Home page: http://www.socr.ucla.edu

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