Homework Quiz 9/30 Find the standard deviation of: 8, 4, 3, 2

Relative Standing and Boxplots Section 3-4

Agenda z-Scores Finding Percentile Finding Quartiles Box Plots Interquartile Range Modified Box Plots

Agenda z-Scores Finding Percentile Finding Quartiles Box Plots Interquartile Range Modified Box Plots

z-Scores What does it meanHow do you find it The z-Score for a particular data point tells you the number of standard deviations the point is away from the mean

Example A man is 76.2 in tall and lb heavy. Which of these measurements is more extreme? Consider that the mean height is in with a standard deviation of 3.02 in. Also the mean weight is lb with a standard deviation of lb. ROUND-OFF RULE: Round z-Scores to the nearest hundredth, as that is how they are typically plugged into statistical tables.

z Scores and Usual Values Whenever a data value is less than the mean, its corresponding z score is negative.

Agenda z-Scores Finding Percentiles Finding Quartiles Box Plots Interquartile Range Modified Box Plots

Percentile What does it meanHow do you find it A percentile tells you what percentage of the data is less than a particular data value ROUND-OFF RULE: Round off to the nearest whole number.

Example The scores on the most recent quiz are posted in the table below. Assume you are the person that scored a 93, and calculate your percentile

Agenda z-Scores Finding Percentile Finding Quartiles Box Plots Interquartile Range Modified Box Plots

Quartiles What does it meanHow do you find it * The data must be ordered least to greatest first. ROUND-OFF RULE: Round L to the nearest whole number unless it is exactly at.5, then find the average of the #’s it is in between.

5-Number Summary What does it meanWhy do we do it? The 5-Number Summary gives us all of the information we need in order to create a box plot (which we will learn next)

Example Find the 5-Number Summary for the following data set:

Important – Remember the Difference! StatisticParameter Mean Standard Deviation Variance z score

Homework P : #7, 8, 15-18, 27(only complete 5 # summary)

Section 3.4 Day 2

Homework Quiz 10/2 Write down all of your work for problem #8

Agenda z-Scores Finding Percentile Finding Quartiles Box Plots Interquartile Range Modified Box Plots

Agenda z-Scores Finding Percentile Finding Quartiles Box Plots Interquartile Range Modified Box Plots

Box Plots How to construct itWhy do we do it? Gives us an idea about the distribution, spread, and center of the data Great for comparing two sets of data

Example Create a box plot using the following data about the number of times Abena solved a rubik’s cube in a single minute

M ATH S WAGG – C ALCULATOR S KILLZ

Critical Thinking Compare the given data sets Each plot represents a different lottery years and the average earnings for the winning contestants. Lottery 1 is in 2010 Lottery 2 is in 2011 Lottery 3 is in 2012

Critical Thinking Compare the given data sets

Agenda z-Scores Finding Percentile Finding Quartiles Box Plots Interquartile Range Modified Box Plots

Interquartile Range How to find itWhy do we do it?

Agenda z-Scores Finding Percentile Finding Quartiles Box Plots Interquartile Range Modified Box Plots

Modified Box Plot What is it?Why do we do it? A modified box plot follows the same procedure as a normal box plot, except you distinguish outliers using asterisks and stop your line at the least and greatest values that aren’t outliers. Outliers can significantly effect the shape of the data, so using the modified box plot makes are representation resistant.

Example Create a modified box plot using the following data about the number of times Ms. P served an ace against Mitch after school at the tennis courts. ACES

Homework P : #4, 11, 14, 27, 28