Holt McDougal Algebra 1

10-3-EXT Dot Plots and Distributions10-3-EXT Dot Plots and Distributions

Holt Algebra 1

Lesson PresentationLesson Presentation

Holt McDougal Algebra 1

Holt McDougal Algebra 1

10-3-EXT Dot Plots and Distributions

Create dot plots.

Use a dot plot to describe the shape of a data distribution.

Objectives

Holt McDougal Algebra 1

10-3-EXT Dot Plots and Distributions

dot plotuniform distributionsymmetric distributionskewed distribution

Vocabulary

Holt McDougal Algebra 1

10-3-EXT Dot Plots and Distributions

A dot plot is a data representation that uses a number line and x’s, dots, or other symbols to show frequency. Dot plots are sometimes called line plots.

A dot plot gives a visual representation of the distribution, or “shape”, of the data. The dot plots in Example 1 have different shapes because the data sets are distributed differently.

Holt McDougal Algebra 1

10-3-EXT Dot Plots and Distributions

Holt McDougal Algebra 1

10-3-EXT Dot Plots and Distributions

Example 1 and 2 :Making a Dot Plots and Shapes of Distribution

Gloria is collecting different recipes for chocolate chip cookies. The table shows the cups of flours needed in the recipes. Make a dot plot showing the data. Determine the distribution of the data and explain what the distribution means.

Holt McDougal Algebra 1

10-3-EXT Dot Plots and Distributions

Example 1 and 2 : Continued

Find the least and greatest number in the cups of flour data set. Then use the values to draw a number line. For each recipe, place a dot above the number line for the number of cups of flour used in the recipe.

12

0 1 1 12 2 2 1

2 3

Amount of Flour Recipes

Cup

Holt McDougal Algebra 1

10-3-EXT Dot Plots and Distributions

Example 1 and 2 : Continued

The distribution is skewed to the right, which means most recipes require an amount of flour greater than the mean.

Holt McDougal Algebra 1

10-3-EXT Dot Plots and Distributions

Check It Out! Example 1 The cafeteria offers items at six different prices. John counted how many items were sold at each price for one week. Make a dot plot of the data.

Find the least and greatest number in the price data set. Then use the values to draw a number line. For each item, place a dot above the number line for the cost of that item.

Holt McDougal Algebra 1

10-3-EXT Dot Plots and Distributions

Check It Out! Example 1 Continued

1.5 2 2.5 3.5 4.53 4

Holt McDougal Algebra 1

10-3-EXT Dot Plots and Distributions

Check It Out! Example 2

Data for team C members are shown below. Make a dot plot and determine the type of distribution. Explain what the distribution means.

Holt McDougal Algebra 1

10-3-EXT Dot Plots and Distributions

Check It Out! Example 2 Continued

3 4 5 6

The data distribution is uniform. All team members ran about the same distance.