## Chapter 3 - Statistics

**Prescribed Learning Outcomes:**

E1 Solve problems that involve measures of central tendency, including: mean, median, mode, weighted mean, trimmed mean.

E2 Analyze and describe percentiles.

## Chapter 3 key ideas

- Calculate the mean, median and mode of a set of data.
- Explain how outliers skew results and calculate trimmed means.
- Calculate weighted means.
- Define and calculate percentile ranking.

## 3.1 Mean, Median and Mode

In this section you will use a stem and leaf plot to organize sets of numbers. Then you will find the mean, median and mode for the sets.

Please watch the mean, median, and mode video and do page 110 #1-2, page 112 #3-5, page 113 #6-8, page 116 #9-10, page 118 #11-3, and page 120 #1-5.

Please watch the mean, median, and mode video and do page 110 #1-2, page 112 #3-5, page 113 #6-8, page 116 #9-10, page 118 #11-3, and page 120 #1-5.

## 3.2 Weighted and Trimmed Means and Outliers

An outlier is a piece of data that does not fit with the rest of the pieces of data. It is either too large or too small so it skews the mean. A trimmed mean will often give a more accurate mean.

Weighted means occur when each set of values has a different weighting.

Please watch the weight & trim means and outliers video and do page 124 #1-3, page 126 #4-6, page 128 #7-9, and page 129 #1-5.

Weighted means occur when each set of values has a different weighting.

Please watch the weight & trim means and outliers video and do page 124 #1-3, page 126 #4-6, page 128 #7-9, and page 129 #1-5.

## 3.3 Percentile Ranking

Percentile ranking tells us the percent of the data values that are BELOW the one that we are concerned about. For example, baby weights are ranked by percentile. If our baby has a weight in the 60th percentile it means that 60% of the babies have weights below our baby.

Please watch the percentile ranking video and do page 133 #1-3, page 136 #4-6, page 137 #7-9, and page 139 #1-3.

Please watch the percentile ranking video and do page 133 #1-3, page 136 #4-6, page 137 #7-9, and page 139 #1-3.

## Review for the test

Read the key ideas at the top of this page and ensure that you understand them all.

Mark all of your homework with the answer key in the classroom.

Complete and mark the practice test on page 140.

Mark all of your homework with the answer key in the classroom.

Complete and mark the practice test on page 140.