Homework
Daily Check 2 points each 1. You go to the grocery story to pick up some fruits and veggies. Would you expect the selection to have a high level of variability or low? 2. When you get in the car, you turn the radio to your favorite station. Is there a high or low consistency in the type of music played on that station? 3. Describe the variability and consistency of the following: the math grades of all the 10th grade students at Hillgrove 4. Put the following in order from least to greatest: 0.4, 0.47, 0.042 5. Change to a decimal: 8%, 70%, 0.6%
Alice’s Test Scores: 72, 100, 56, 60, 64, 74, 78 Describe her grades.
Daniel’s Test Scores: 71, 74, 71, 66, 74, 76 Describe his grades.
Alice’s Test Scores: 72, 100, 56, 60, 64, 74, 78 Daniel’s Test Scores: 71, 74, 71, 66, 74, 76 Who’s grade is more consistent? Who’s grade is more variable? Who is the better student?
Mean Alice’s Test Scores: 72, 100, 56, 60, 64, 74, 78 Daniel’s Test Scores: 71, 74, 71, 66, 74, 76
Standard Deviation
Standard Deviation (By hand) Alice’s Scores: 72, 100, 56, 60, 64, 74, 78 1. Find the mean
2. Subtract the mean from each data point Standard Deviation (By hand) Standard Deviation Alice’s Scores: 72, 100, 56, 60, 64, 74, 78 2. Subtract the mean from each data point
3. Square each of the differences Standard Deviation (By hand) Standard Deviation Alice’s Scores: 72, 100, 56, 60, 64, 74, 78 3. Square each of the differences
4. Add up each of the squares Standard Deviation (By hand) Standard Deviation Alice’s Scores: 72, 100, 56, 60, 64, 74, 78 4. Add up each of the squares
5. Divide by the number of data points Standard Deviation (By hand) Alice’s Scores: 72, 100, 56, 60, 64, 74, 78 5. Divide by the number of data points
Standard Deviation (By hand) Alice’s Scores: 72, 100, 56, 60, 64, 74, 78 5. Take the square root
Standard Deviation (calculator) Daniel’s Scores: 71, 74, 71, 66, 74, 76 2nd Data to get the Stat Menu Choose 1-Var and press enter Stat should show at bottom of screen Press DATA Put in each point and frequency Press STATVAR
What do the mean and standard deviation tell us? Alice’s Test Scores: 72, 100, 56, 60, 64, 74, 78 Daniel’s Test Scores: 71, 74, 71, 66, 74, 76 What do the mean and standard deviation tell us?
Find the Mean and Standard Deviation Xi F1 = frequency 10 4 8 5 6 2
Find the Mean and Standard Deviation
Find the Mean and Standard Deviation
Homework: Workbook p. 272-273 #1-13 Just find mean and standard deviation