Stem-and-Leaf & Scatter Plots Absent 1/28,29

Mean: Average Add up all the numbers and divide by how many numbers you have in your data ex: 1, 4, 5, 7, 13 Add them up: Divide by how many numbers you have: 30 5 Mean: 6 Median: Middle Number (hint: the thing in the middle of the road is the MEDIAN) When #s are in order from least to greatest… the middle number (or average of the 2 middle #s) ex: 1, 13, 7, 4, 5 Order Least to Greatest: 1, 4, 5, 7, 13 Median 5

Mode: Most Often (hint: MOde…MOst) Number that occurs most often in the data ex: 1, 2, 5, 2, 1, 6, 1, 3 There are two 2s but there are three 1s… So the Mode is 1 Range: Max-Min How much info (how many #s) does the data cover (from least to greatest) ex: 5, 18, 7, 14, 8, 12, 11 Order Least to Greatest: 5, 7, 8, 11, 12, 14, 18 From 5 to 18, there are 13 numbers Max: 18 Min: 5 Range: 13

Example 1 Mrs. Yuhls students test scores 48, 72, 95, 99, 82, 63, 82, 55, 90, 67, 82 Step 1: Put numbers from 24, 88, 94, 78, 86, 27, 60, 77, 63, 100, 94 least to greatest. 24, 27, 48, 55, 60, 63, 63, 67, 72, 77, Step 2: Fill in all the stems 78, 82, 82, 82, 8 6, 88, 90, 94, 95, 99, 100, 24,7 Step 3: Fill in all the leafs Step 4: Find the median 6 0,3,3,7 80 is the median 72,7,8 82,2,2,6,8Step 6: Find the mode 9 0,4,4,5,9 82 is the mode 100 Step 7: Find the range 76 is the range

Example 2 Mr. Halls students Test Scores 58, 62, 77, 34, 47, 98, 90, 81, 55, 78, 63, 72, 82, 88, 99, 67, 94, 86, 94, 94, 73 34, 47, 55, 58, 62, 63, 67, 72, 73, 77, 78, 81 Step 1: Put numbers from 82, 86, 88, 90, 94, 94, 94, 98, 99 least to greatest Make a back to back stem-and-leaf plot of both sets of test data Step 2: Fill in all the stems Hall Yuhl Step 3: Fill in all the leafs 2 4, Step 4: Find the medians % yuhl 7, 3, 2 6 0, 3, 3, 7 78% Hall 8, 7, 3, 2 7 2, 7, 8 Step 5: Find the modes 8, 6, 2, 1 8 2, 2, 2, 6, 8 82% Yuhl, 94% Hall 9, 8, 4, 4, 4, 09 0, 4, 4, 5, 9 Step 6: Find the ranges % Yuhl, 65% Hall

What is the lowest test score in Mr. Hall class? 34% What is the highest test score in Mrs. Yuhls class? 100% What is the median test score in each class? 82% yuhl 78% Hall How many test scores were in the 70s in each class? 4 scores for Hall, 3 scores for Yuhl How many students got As in both classes? 6 scores for Hall, 5 scores for Yuhl Whose class did better on the test? Explain. Both classes did about the same.

Correlation: Relationship when comparing two things Positive Correlation As one increases (goes up), it causes the other to increase How much a student studies and their grades The number of people attending a movie and the total ticket price for the movie The amount of rain and the size of puddles outside Strong Positive Weak Positive Negative Correlation As one increases (goes up), it causes the other to decrease (go down) The miles you drive and the gas in your cars gas tank The temperature outside and the number of heaters used The speed at which a car is going and the time it takes to reach a destination Strong Negative Weak Negative

No Correlation There is no relationship between the two things being compared Your shoe size and your grades The length of your hair and the number of friends you have The temperature outside and the time you eat dinner