1. Homework

2. 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%

3. Alice’s Test Scores: 72, 100, 56, 60, 64, 74, 78
Describe her grades.

4. Daniel’s Test Scores: 71, 74, 71, 66, 74, 76
Describe his grades.

5. 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?

6. Mean Alice’s Test Scores: 72, 100, 56, 60, 64, 74, 78
Daniel’s Test Scores: 71, 74, 71, 66, 74, 76

7. Standard Deviation

8. Standard Deviation (By hand)
Alice’s Scores: 72, 100, 56, 60, 64, 74, 78
1. Find the mean

9. 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

10. 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

11. 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

12. 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

13. Standard Deviation (By hand)
Alice’s Scores: 72, 100, 56, 60, 64, 74, 78
5. Take the square root

14. 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

15. 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?

16. Find the Mean and Standard DeviationXi
F1 = frequency 10 4 8 5 6 2

17. Find the Mean and Standard Deviation

18. Find the Mean and Standard Deviation

19. Homework: Workbook p. 272-273 #1-13 Just find mean and standard deviation