## Estimated Lesson Duration:

1-2 class periods

## Overview:

Students use data collected at Let’s Get Healthy! school events to 1) learn the differences between observational studies and experiments; 2) apply descriptive statistics to data; 3) construct and interpret confidence intervals; and 4) perform statistical hypothesis testing with authentic Let’s Get Healthy! data.

This lesson is designed to introduce students to the concept of confidence intervals for sample means and the reason for the sample size requirement when data is not normally distributed. The exercise uses data from the “Let’s Get Healthy” health fairs conducted in 2010-2011 school year from nine middle schools from eight school districts. The exercise is designed so that individual students take small (n=10) and large (n=35) random samples from either the female or male population, generate confidence intervals for population means from the samples, provide a class plot of the confidence intervals compared to the known population mean and then compare the results of the two sample sizes in relation to the generated intervals containing the true population mean for these skewed populations.

## Key Concepts and Standards:

Key Concepts: Confidence intervals, population mean, data, random sample, generate, class plot, statistics

Standards: This lesson covers several Common Core State Standards in Statistics and Probability.

## Preparations/ Materials

• “Let’s Get Healthy” Statistics lesson plan.

• TI-83, 84, or Inspire calculator.

• Figure 1. BMI distribution graph.

• Excel File – “LGH Statistics Exercise Data”

• Either computers with Excel to access Excel files or printouts of the Female and Male BMI pages included with this document