UA · Unit 7 review

1. 1.

   Is this a statistical question? “How many minutes do sixth graders spend on homework?”

   Answer. statistical — answers vary

   statistical — answers vary

2. 2.

   The dot plot shows hours of sleep. How many students slept 10 hours?

   Answer. 1

   Count the dots above 10: 1.

3. 3.

   Find the IQR of 4, 5, 6, 8, 10, 11, 13.

   Answer. 6

   Q1 = 5, Q3 = 11, IQR = 11 − 5 = 6.

4. 4.

   The data set is 6, 8, 10, 12. The mean is 9. Find the MAD.

   Answer. 2

   Mean of the distances from 9 is 2.

5. 5.

   Two classes have the same mean score. Class A’s scores are tightly clustered; Class B’s are spread out. Which class has the greater MAD? Write a complete answer — Theo will compare with a partner.

   Answer. Class B

   Greater spread means a greater mean absolute deviation.

6. 6.

   Is this a statistical question? “How many minutes do sixth graders spend on homework?” Write a complete answer — Jonah will compare with a partner.

   Answer. statistical — answers vary

   statistical — answers vary

7. 7.

   The dot plot shows hours of sleep. How many students slept 10 hours? Then Sam needs 5 of that amount. What is the total they need?

   Answer. 15

   Count the dots above 10: 3. Then multiply by 5: 15.

8. 8.

   Find the median of 8, 9, 10, 12, 14, 15, 17. Then Mei needs 4 of that amount. What is the total they need?

   Answer. 48

   Ordered already. Middle value is 12. Then multiply by 4: 48.

9. 9.

   Find the mean of 4, 6, 8, 10. Then Sam needs 4 of that amount. What is the total they need?

   Answer. 28

   Sum = 28; divide by 4 → 7. Then multiply by 4: 28.

10. 10.

    Two classes have the same mean score. Class A’s scores are tightly clustered; Class B’s are spread out. Which class has the greater MAD? Write a complete answer — Ava will compare with a partner.

    Answer. Class B

    Greater spread means a greater mean absolute deviation.

11. 11.

    Think

    Grace tried this problem:
    Is this a statistical question? “How many pets do students in this class have?”
    Grace wrote statistical — answers vary (check this). That is not correct. What is the right answer?

    Answer. statistical — answers vary

    Grace’s answer statistical — answers vary (check this) is off. statistical — answers vary

12. 12.

    Think

    Priya tried this problem:
    The dot plot shows hours of sleep. How many students slept 7 hours?
    Priya wrote -1. That is not correct. What is the right answer?

    Answer. 1

    Priya’s answer -1 is off. Count the dots above 7: 1.

Original extra practice. Keys are computed from the items, not guessed.