Statistics Practice Test

Name: ______________________   Date: __________   Score: ____ / 30

30 questions. Calculator allowed. Show your working. steplyclass.com/university-statistics/practice-test/

1. 1

   x: 0, 1, 2, 3; P(x): 0.1, 0.3, 0.4, 0.2, find the mean
   1. A) 1.5
   2. B) 17
   3. C) 1
   4. D) 1.7

2. 2

   X: 1, 2, 3, 4, 5; P(x): 0.1, 0.2, 0.3, 0.3, 0.1, find the expected value
   1. A) 1
   2. B) 31
   3. C) 3
   4. D) 3.1

3. 3

   x: 0, 1, 2, 3, 4; P(x): 0.05, 0.15, 0.4, 0.3, 0.1, find the mean

   Answer: ____________________

4. 4

   Poisson mean 2, P(X = 3)
   1. A) 6
   2. B) 2
   3. C) 0.1804
   4. D) 1

5. 5

   A road has an average of 3 accidents a week, probability of exactly 1 accident in a week
   1. A) 3
   2. B) 0.1494
   3. C) 1
   4. D) 1.494

6. 6

   Poisson mean 2.5, P(X <= 2)

   Answer: ____________________

7. 7

   Find the probability of success 0.2, P(first success on try 3).
   1. A) 128
   2. B) 0.1024
   3. C) 0.1280
   4. D) 0.2

8. 8

   Roll a die until a 6, P(first 6 on roll 4)
   1. A) P(X = 4) ≈ 0.0965
   2. B) P(X = 4) ≈ 0.00965
   3. C) 0.0804
   4. D) P(X = 4) ≈ 0.965

9. 9

   Find the probability of success 0.05, expected number of tries.

   Answer: ____________________

10. 10

    Normal: P(X < 60), mean 50, sd 10
    1. A) P(X < 60) = 0.08413
    2. B) P(X < 60) = 8.413
    3. C) P(X < 60) = 0.8413
    4. D) P(X < 60) = 1

11. 11

    Normal: P(40 < X < 65), mean 50, sd 10
    1. A) 0.7745
    2. B) 7.745
    3. C) 1.5
    4. D) 0.07745

12. 12

    Normal: P(X < 480), mean 500, sd 25

    Answer: ____________________

13. 13

    Normal mean 50, sd 10: value with 90% below it
    1. A) 0.9
    2. B) 628
    3. C) 6.28
    4. D) 62.8

14. 14

    Normal mean 100, sd 10: top 2.5%
    1. A) 11960
    2. B) 119.6
    3. C) 80.4
    4. D) 0.975

15. 15

    Calculate 33rd percentile, mean 50, sd 10

    Answer: ____________________

16. 16

    Samples of 36 from mean 50, sd 12: P(sample mean > 53)
    1. A) 1.5
    2. B) 50
    3. C) 0.0668
    4. D) 0.4013

17. 17

    Samples of 100 from mean 500, sd 50: P(sample mean > 510)
    1. A) 0.4207
    2. B) 0.0228
    3. C) 2
    4. D) 500

18. 18

    Samples of 9 from mean 60, sd 6: P(sample mean > 64)

    Answer: ____________________

19. 19

    Calculate 95% confidence interval: mean 50, sd 8, n 64
    1. A) (48.04, 51.96)
    2. B) (49.755, 50.245)
    3. C) (51.96, 48.04)

20. 20

    Calculate 95% confidence interval: mean 64.5, sd 7, n 49
    1. A) (66.46, 62.54)
    2. B) (62.54, 66.46)
    3. C) (64.22, 64.78)

21. 21

    Calculate 90% confidence interval: mean 5.6, sd 1.5, n 20

    Answer: ____________________

22. 22

    95% confidence interval: sample mean 50, sample sd 8, n 16

    Answer: ____________________

23. 23

    98% confidence interval: sample mean 100, sample sd 12, n 9

    Answer: ____________________

24. 24

    98% confidence interval: sample mean 9, sample sd 1.5, n 15

    Answer: ____________________

25. 25

    Calculate 95% confidence interval: 120 of 400 say yes

    Answer: ____________________

26. 26

    Calculate 99% confidence interval: 300 of 1000 own a car

    Answer: ____________________

27. 27

    Calculate 90% confidence interval: 410 of 820 agree

    Answer: ____________________

28. 28

    Sample size: 95% confidence, sd 15, error bound 2
    1. A) n = 217
    2. B) n = 216
    3. C) n = 0.9750
    4. D) n = 216.09

29. 29

    Sample size: 95% confidence, sd 6, error bound 1.5
    1. A) n = 620
    2. B) n = 62
    3. C) n = 0.9750
    4. D) n = 61

30. 30

    Sample size for a proportion: 95% confidence, error bound 0.02

    Answer: ____________________