Statistics Second Semester Review Answers

CHAPTER 2

1a) upper limit = 100 lower limit = 53 range = 47

b) width = 5

Class Limits	Boundaries	Midpoints	Frequency	Cumulative Frequency	Relative Frequency
51 -55	50.5 – 55.5	53	3	3	.15
56 – 60	55.5 – 60.5	58	1	4	.05
61 – 65	60.5 – 65.5	63	1	5	.05
66 – 70	65.5 – 70.5	68	2	7	.10
71 – 75	70.5 – 75.5	73	0	7	0
76 – 80	75.5 – 80.5	78	0	7	0
81 – 85	80.5 – 85.5	83	2	9	.10
86 - 90	85.5 – 90.5	88	4	13	.20
91 – 95	90.5 – 95.5	93	4	17	.20
96 - 100	95.5 – 100.5	98	3	20	.15

c) x-axis is labeled with BOUNDARIES and bars are drawn to frequency

CHAPTER 3

1a) Mean = 79.9 Median = 86.5 Mode = 53, 89, 91 Midrange = 76.5

b) s = 16.3

c)

5	3 3 5
6	0 2 6
7	0
8	1 2 6 7 9 9
9	1 1 2 4 8 9
10	0

d) Min 53 Q₁ 64 Med 86.5 Q₃ 91.5 Max 100

e) 22.5% f) 93 2) 83.2%

3a) 8.2 b) 7 – 9 (or the midpoint 8) c) 4.6 (sample)

CHAPTER 4

1a) 1/3 b) .09 (or 1/11)

2a) .28 b) .716

3) There are no common outcomes between events. Example: Dog or Cat

4) Permutation: order matters. Combination: order does not matter

5) 2100 6) 4.76 x 10¹³ 7) 177,100

8) 5040 9) 1/3,838,380 or 2.605 x 10^-7

CHAPTER 5

1a) .001 b) .3439

2) .00000625 3) .2508

4) .5518 5) mean 4.18 standard deviation 1.31

6) -$70.00 7) mean 4.5 standard deviation 1.98

CHAPTER 6

1) Standard normal distribution has a mean = 0 and a standard deviation = 1

2) For distribution of sample means

3) .0502 4a) z = 1.27 b) .1016

5a) .0013 b) 50% c) .0082

6) .0569 7) .2621

CHAPTER 7

1) z-test for n greater than or equal to 30; t-test for n less than 30

2) 3) (if p-hat unknown use 0.5)

4) 3.49 < μ < 3.90 5) .7608 < p < .8392

6) 7.5236 < μ < 9.4139 7) 2.2316 < μ < 2.3684

8) 345.667< μ < 51.533 9) 190 people

10) 404 people 11) .656 < p < .744

CHAPTER 8

1) H₀ null hypothesis H₁ alternate hypothesis

2a) p = .1498

2b) H₀: μ ≤ 32 H₁: μ > 32 (claim) p = .0076 Reject H₀

2c) H₀: p ≤ .5 H₁: μ > .5 (claim) p = .0912

Do not reject H₀

2e) H₀: p = .6 (claim) H₁: p ≠ .6 p = .7469

Do not reject H₀