Understanding and Comparing Distributions Ch 5 Day 1

Understanding and Comparing Distributions Ch. 5 Day 1 Notes AP Statistics EQ: How do we make boxplots and why? How do we compare distributions?

Examples of Boxplots

• • Boxplots Title Scale on horizontal axis Label the five number summary(Min, Q 1, Med, Q 3, Max) • Make sure to use the modified boxplot option on your calculator. (the one that shows outliers out to the sides) • Are good for side to side comparison but do not show individual values

Boxplots Use your Calculator Make a boxplot for the test scores of 15 employees enrolled in a CPR class: 13 21 5 9 7 18 18 10 37 15 11 16 14 20 17

What does it look like and what does this boxplot tell us about our data?

To find outliers: Outliers 1. Find the IQR 2. Q 1 - 1. 5 IQR (lower boundary) 3. Q 3 + 1. 5 IQR (upper boundary) Anything below the lower number and above the larger number is considered an outlier.

Describe the box plot below

Steps to comparing boxplots 1. 2. 3. 4. Identify what you are comparing Show mechanics(5 # summary, IQR) Make a picture Conclusion(shape, center, spread) Compare means to link the two data sets together in one sentence. For example, the east is more symmetric than the west.

C o m p a r e

Which of the following distributions are more likely to be skewed to the right than skewed to the left? I. Household incomes II. Home prices III. Ages of teenage drivers A. II only B. I and II C. I and III D. II and III E. I, II, and III

Which of the following are true statements? A. The range of the sample data is never greater than the standard deviation. B. The IQR is half the distance between the first quartile and the third quartile. C. While the range is affected by outliers, the IQR is not.

True or False. • 1. The second quartile is the median of an ordered data set. True • 2. The five numbers you need to graph a boxplot are the minimum, the maximum, first quartile, third quartile, and the mean. False

Homework P. 95 # 4, 7, 11, 16, 19, 21, 25 Tomorrow In Class: Ch. 4 Quiz HW: Ch. 5 Reading Questions