Measures of Central Tendency Algebra 1(B) Statistics

Today’s Schedule Class Attendance / Announcements Multiple Choice Warm-Up Homework Check / Questions Measures of Central Tendency Notes / Practice Brain Break Mean, Median, and Mode Numbers Game Exit Slip Begin Homework

Multiple Choice Warm-Up Do your best on the following problems. Remember: try to eliminate answers you know are not correct! 1. 3. 2.

Homework Check / Questions pgs. 371, 373 #9, 13-16, 34

Objectives Understand and apply the measures of central tendency Recognize situations in which one measure of central tendency is more reliable than another Vocabulary: measures of central tendency, mean, median, mode

What is the Mean? Mean: the “average” of a set of data found by… Adding the data in the set and… Dividing that sum by the number of elements in the set. Example: Find the mean of the collection of numbers: 6, 5, 7, 5, 3, 4

Finding the Mean A football team had offensive drives of 43, 42, 45, 44, 45, and 48 yards. Find the mean offensive drive for the team. 44.5 yards

Finding the Mean The heights of the players on Oswego High School’s basketball team are 72”, 74”, 70”, 78”, 75”, and 70”. Find the mean height. Round your answer to the nearest tenth. 73.2 inches

Finding the Mean The high temperatures for a 7-day week during December in Oswego were 29°, 31°, 28°, 32°, 29°, 27°, and 62°. Find the mean high temperature for the week. 34° Is 34° a good representation of a typical week in Oswego in December. Why or why not? Discuss this question with your partner for one minute You will be asked to support your reasoning

What is the Median? Median: the middle number of a set of data when the numbers are arranged in numerical order. Example: Find the median of the collection of numbers: 2, 16, 9, 10, 20, 5, 1, 10, 23 10 1, 2, 5, 9, 10, 10, 16, 20, 23

Finding the Median The rainfall in the month of April in Oswego over the past 5 years has been 3.6”, 2.92”, 3.62”, 3.2”, and 3.37”. Find the median amount of rainfall in April. 3.37 inches

Finding the Median Find the median of the collection of numbers: 17, 20, 2, 8, 17, 14, 20, 13, 5, 10 What should we do if there is no middle number? Find the average of the two middle numbers! 13.5

What is the Mode? Mode: the number that occurs most often in a set of data. Hint: It will help to arrange numbers in numerical order. Example: Find the mode of the collection of numbers: 1, 12, 4, 5, 4, 8, 2 1, 2, 4, 4, 5, 8, 12 1, 2, 4, 4, 5, 8, 12

Finding the Mode Your homework scores in math this semester have been 89%, 100%, 96%, 77%, 80%, 96%, 88%, and 83%. What is the mode of your homework scores? 96%

We call a set of data bimodal if it has two modes. Finding the Mode Find the mode of the collection of numbers: 70, 55, 60, 28, 55, 68, 70, 40 55 and 70 We call a set of data bimodal if it has two modes. Find the mode of the collection of numbers: 12, 8, 15, 17, 5, 3, 11, 9 No mode

Brain Break Skate on thin ice Up for grabs Take 2-3 minutes to get up, stretch out, talk to a neighbor, or try the following rebus puzzles… Skate on thin ice Up for grabs

Round decimals to nearest whole number! Mean, Median, Mode Numbers Game Instructions: You will be divided into groups of 4. When you are sitting with your group, turn your desks to face each other. Determine an order (who will go first, second, third, and fourth). There will be two piles of cards: a numbers pile and a M-M-M (mean-median-mode) pile. The first person will draw cards from the numbers pile. Each person in the group is in charge of finding the mean, median, and mode of the collection of numbers. The same person will then draw from the M-M-M pile. This will determine the number of points Person 1 will get. Repeat Steps 4 and 5 until everyone has gone. Round #1  draw 3 cards Round #2  draw 4 cards Round #3  draw 5 cards Round #4  draw 6 cards Round #5  draw 7 cards Round decimals to nearest whole number!

After the Game… Report your game results to a teacher Paperclip the number cards and the M-M-M cards together You may begin working on the homework assignment if you finish before the time limit Homework: pgs. 371-372 #19-29

Mean, Median and Mode Song Exit Slip Work on this individually Needs to be done before you leave Begin working on the homework after you turn it in Homework: pgs. 371-372 #19-29 Mean, Median and Mode Song