How do you graphically show the heights of the students in your - PowerPoint PPT Presentation

How do you graphically show the heights of the students in your class?

In this lesson you will learn how to construct box plots by finding the medians of the data.

Let’s Review Measures of Center Median (middle) – order the numbers from least to greatest and find the middle number 3 8 6 12 4 3 4 6 8 12 5 12 7 9 2 10 2 5 7 9 10 12 8

Let’s Review Measures of Center Range – the difference between the maximum and minimum values 5 6 9 12 14 14 – 5 = 9

Core Lesson Heights of students in inches 52 55 57 54 56 50 56 53 57 65 53 56 54 58 Organize the data from least to greatest.

Core Lesson 50 52 53 53 54 54 55 56 56 56 57 57 58 64 To draw a box plot, you need 5 values: Minimum, Maximum, Median, Lower Quartile and Upper Quartile What are quartiles? Quartiles are values that divide the data set into fourths

Core Lesson 50 52 53 53 54 54 55 56 56 56 57 57 58 65 Minimum = 50 Median = 55.5 Lower Quartile = 53 Maximum = 65 Upper Quartile = 57

Core Lesson Draw a number line that includes your minimum and maximum points. 48 50 52 54 56 58 60 62 64 66

Core Lesson Draw a point for the median. Then, draw points for the lower and upper quartiles. 48 50 52 54 56 58 60 62 64 66

Core Lesson Draw a box using the upper and lower quartiles as sides. Draw a line through the median. 48 50 52 54 56 58 60 62 64 66

Core Lesson Draw points for the minimum and maximum values. Connect the points to the box with a line. 48 50 52 54 56 58 60 62 64 66

Core Lesson What were all these dots again? Median Maximum Value Minimum Value Lower Quartile – Quartile 1 Upper Quartile – Quartile 3 48 50 52 54 56 58 60 62 64 66

A Common Misunderstanding Why isn’t the first dot the first quartile? Lower Quartile – Quartile 1 Minimum Value 48 50 52 54 56 58 60 62 64 66

Core Lesson How is the data distributed? 1/2 of the data is in the box 1/4 of the data is in the 1/4 of the data is in the upper quartile lower quartile 48 50 52 54 56 58 60 62 64 66

Core Lesson What is the range of the data? 65 – 50 = 15 48 50 52 54 56 58 60 62 64 66

In this lesson you have learned how to construct box plots by finding the medians of the data.