Appendices

# Appendix A-1: Solutions to Review Exercises (Ch 3-13)

Barbara Illowsky & OpenStax et al.

## Chapter 3

**1.** c. parameter

**2.** a. population

**3.** b. statistic

**4.** d. sample

**5.** e. variable

**6.** quantitative continuous

**7.**

**8.** Answers will vary.

## Chapter 4

**9.** c. (0.80)(0.30)

**10.** b. No, and they are not mutually exclusive either.

**11.** a. all employed adult women

**12.** 0.5773

**13.** 0.0522

**14.** b. The middle fifty percent of the members lost from 2 to 8.5 lbs.

**15.** c. All of the data have the same value.

**16.** c. The lowest data value is the median.

**17.** 0.279

**18.** b. No, I expect to come out behind in money.

**19.** *X* = the number of patients calling in claiming to have the flu, who actually have the flu.

*X* = 0, 1, 2, …25

**20.** *B*(25, 0.04)

**21.** 0.0165

**22.** 1

**23.** c. quantitative discrete

**24.** all words used by Tom Clancy in his novels

## Chapter 5

**25.**

**26.** qualitative

**27.** 0.36

**28.** 0.7636

**29.**

**30.** *B*(10, 0.76)

**31.** 0.9330

**32.**

*X*= the number of questions posted to the statistics listserv per day.

*X*= 0, 1, 2,…

*X*~

*P*(2)

**33.** $150

**34.** Matt

**35.**

**36.** 16

**37.** first quartile: 2

second quartile: 2

third quartile: 3

**38.** 0.5

**39.** 715

**40.** 215

## Chapter 6

**41.**

**42.**

*P*(

*x*<

*k*) = 0.65 = (

*k*– 3)(110).

*k*= 9.5

**43.**

**44.** d. *G* and *H* are independent events.

**45.**

*J*and

*K*are independent so they are not mutually exclusive which would imply dependency (meaning

*P*(

*J*AND

*K*) is not 0).

*P*(

*J*OR

*K*) =

*P*(

*J*) +

*P*(

*K*) –

*P*(

*J*AND

*K*) =

*P*(

*J*) +

*P*(

*K*) –

*P*(

*J*)

*P*(

*K*) = 0.3 + 0.6 – (0.3)(0.6) = 0.72. Note the

*P*(

*J*AND

*K*) =

*P*(

*J*)

*P*(

*K*) because

*J*and

*K*are independent.

*J*and

*K*are independent so

*P*(

*J*) =

*P*(

*J*|

*K*)

**46.** a. *P*(5)

## Chapter 7

**47.** a. *U*(0, 4)

**48.** b. 2 hour

**49.** a. 14

**50.**

**51.** c. 5 years

**52.** c. exponential

**53.** 0.63

**54.** *B*(14, 0.20)

**55.** *B*(14, 0.20)

## Chapter 8

**56.** c. the mean amount of weight lost by 15 people on the special weight loss diet.

**57.** 0.9951

**58.** 12.99

**59.** c. 12

**60.** b. 0.60

**61.** c. *N*(60, 5.477)

**62.** 0.9990

**63.** a. eight days

**64.** c. 0.7500

**65.** a. 80%

**66.** b. 35%

**67.** b. no

**68.** b. quantitative continuous

**69.** c. 150

**70.** d. 0.06

**71.** c. 0.44

**72.** b. 0

## Chapter 9

**73.** d. Matt is shorter than the average 14 year old boy.

**74.** Answers will vary.

**75.**

x |
Relative Frequency | Cumulative Relative Frequency |
---|---|---|

1 | 0.3 | 0.3 |

2 | 0.2 | 0.2 |

4 | 0.4 | 0.4 |

5 | 0.1 | 0.1 |

**76.**

**77.** *M* = 3; *Q*_{1} = 1; *Q*_{3} = 4

**78.** 1 and 4

**79.** d. 870

**80.** c. 4070

**81.** a. 919

**82.** b. false

**83.** b. false

**84.** b. false

**85.**

*X*= the number of pies Lee bakes every day.

*P*(20)

**86.** CI: (5.25, 8.48)

**87.**

## Chapter 10

**88.** 77100

**89.** 1242

**90.**

**91.** *N*(180, 16.43)

**92.** a. The distribution for X⎯⎯⎯ is still uniform with the same mean and standard deviation as the distribution for *X*.

**93.** c. The distribution for ∑X is normal with a larger mean and a larger standard deviation than the distribution for *X*.

**94.** N(2, 0.2516√)

**95.** Answers will vary.

**96.** 0.5000

**97.** 7.6

**98.** 5

**99.** 0.9431

## Chapter 11

**100.** 7.5

**101.** 0.0122

**102.** *N*(7, 0.63)

**103.** 0.9911

**104.** b. Exponential

**105.**

**106.** Answers will vary.

**107.** Student’s *t* with *df* = 15

**108.** (560.07, 719.93)

**109.** quantitative continuous data

**110.** quantitative discrete data

**111.**

*X*= the number of patients with a shotgun wound the emergency room gets per 28 days

*P*(4)

**112.** greater than

**113.** No; *P*(*x* = 8) = 0.0348

**114.** You will lose $5.

**115.** Becca

**116.** 14

**117.** Sample mean = 3.2

Sample standard deviation = 1.85

Median = 3

*Q*_{1} = 2

*Q*_{3} = 5

*IQR* = 3

**118.** d. *z* = –1.19

e. 0.1171

f. Do not reject the null hypothesis.

**119.** We conclude that the patient does have the HIV virus when, in fact, the patient does not.

**120.** c. *z* = 2.21; *p* = 0.0136

d. Reject the null hypothesis.

e. We conclude that the proportion of Californian professionals that wear jeans to work is greater than the proportion of non-Californian professionals when, in fact, it is not greater.

f. We cannot conclude that the proportion of Californian professionals that wear jeans to work is greater than the proportion of non-Californian professionals when, in fact, it is greater.

**121.** c. dependent means

**122.** *t*_{5}

## Chapter 12

**123.** (0.0424, 0.0770)

**124.** 2,401

**125.** Check student’s solution.

**126.** 0.6321

**127.** $360

**128.** N(72, 725√)

## Chapter 13

**129.** 0.02

**130.** 0.40

**131.** 100140

**132.** 1060

**133.** *p*-value = 0; Reject the null hypothesis; conclude that they are dependent events

**134.** 8.4

**135.** *B*(14, 0.60)

**136.** d. Binomial

**137.** 0.3669

**138.** *p*-value = 0.0006; reject the null hypothesis; conclude that the averages are not equal

**139.** *p*-value = 0; reject the null hypothesis; conclude that the proportion of males is higher

**140.** Minimize *α* and *β*

**141.**

*P*(

*M*AND 30+) = 0

**142. **1238

**143.** No; *p*-value = 0

**144.** a. uniform

# References

Data from the *San Jose Mercury News*.

Baran, Daya. “20 Percent of Americans Have Never Used Email.” Webguild.org, 2010. Available online at: http://www.webguild.org/20080519/20-percent-of-americans-have-never-used-email (accessed October 17, 2013).

Data from *Parade Magazine*.