Homework 5 Solutions

1. Page 198, #12

μ = 19, σ = 2.5

Interval: μ ± 2 σ

= (19 – 2(2.5) , 19 + 2(2.5)) = (14, 24)

2. Page 199, #16

Curve (a) better represents this distribution. It appears that the mean is approximately 4.2 in (a), and is o in (b). Also, it looks like approximately 68% of the data lies between 3.95 and 4.45, which is 1 standard deviation away from the mean.

3. Page 200, #24

4. Page 201, #26

5. Page 210, #8

(a)

(b) x = μ + 3σ = 36 + (3)(4) = 48 days

If you want to obtain information on the lifespan of 200 fruit flies, you should run the experiment for 48 days.

6. Page 210, #10

(a)

(b)

7. Page 211, #22

.5987

8. Page 211, #24

1-.0401 = .9599

9. Page 211, #34

P( -2.88 < Z < .97) = P(Z < .97) – P(Z < -2.88) = .8340 - .0020 = .8320

10. Page 217, #4

11. Page 218, #10

12. Page 219, #16

13. Page 230, #6

Note: Also needed to include graph.

14. Page 232, #18

15. Page 233, #24

16. Page 242, #16

17. Page 243, #22