1. Objective: to review and use different measures of center

Measures of center  “Americans watch an average of four hours of TV each day.”  “Half of the population polled had five or more people living in their home.”  “When asked how many colleges they applied to, the most frequent answer given by graduating seniors was three.”

Measures of center—what are they?  Mean: the average (how to find: the sum of the data values divided by the number of data items) -good to use when data sets are clustered  Median: The middle number in an ordered list of numbers. Good to use when data set has values that are much larger or smaller than most of the data How to find the median if there is an: Odd number of data items: the middle value Even number of data items: the (mean) average of the 2 middle values.  Mode: the number that occurs the most. Good to use when the data set has some of the same value or when the data isn’t numerical.

example  The following data set shows the number of people who attended a movie theater over a period of 16 days. {14, 23, 10, 21, 7, 80, 32, 30, 92, 14, 26, 21, 38, 20, 35, 21} Find the mean, median, mode

How to find the mean {14, 23, 10, 21, 7, 80, 32, 30, 92, 14, 26, 21, 38, 20, 35, 21} 1. FIND THE SUM (ADD UP THE NUMBERS.) 2. DIVIDE BY THE NUMBER OF DATA VALUES 484

Find the median {14, 23, 10, 21, 7, 80, 32, 30, 92, 14, 26, 21, 38, 20, 35, 21} 1. Put in numerical order 2. 7, 10, 14, 14, 20, 21, 21, 21, 23, 26, 30, 32, 35, 38, 80, 92 Median: = 2 22

MODE  7, 10, 14, 14, 20, 21, 21, 21, 26, 30, 32, 35, 38, 80, 92  What is the mode?  Answer: 21  Note: no mode could be an answer for some data sets.

Question:  The theater’s management wants to compare its attendance to that of other theater’s in the area. Which measure of center BEST represents the data? Please explain your answer.  Review: Mean: Median: 22 Mode: 21

Two more terms  Outliers: a value far from the other values in the data set.  Range Maximum number minus minimum number Outliers: Range: 80, 92 7, 10, 14, 14, 20, 21, 21, 21, 26, 30, 32, 35, 38, 80, – 7 =85

Find the mean, median, mode for the given information. Number of hours of sleep Mean: = =6.68 Median: 5, 5.5, 6, 6, 6, 6.5, 6.5, 6.5, 6.5, 7, 7, 8, 8, 9 =6.5 Mode: =6.5 5, 9, 5.5, 6, 6, 6.5, 6, 6.5, 7, 8, 7, 8, 6.5, 6.5

How many calories do I need to consume on Sunday in order to have an average of 2000 calories per day for a week given the following information? MonTuesWedThursFridaySatSun X X = ,200 + x = 14,000 x = 1800

assignment  Page 188: 1-4, 6-8, 11