of 18¢. Do the data support the claim at the 1% level?
Exercise 9.16.7
(Solution on p. 425.)
An article in the San Jose Mercury News stated that students in the California state university
system take 4.5 years, on average, to finish their undergraduate degrees. Suppose you believe that
the mean time is longer. You conduct a survey of 49 students and obtain a sample mean of 5.1 with
a sample standard deviation of 1.2. Do the data support your claim at the 1% level?
Exercise 9.16.8
The mean number of sick days an employee takes per year is believed to be about 10. Members
of a personnel department do not believe this figure. They randomly survey 8 employees. The
number of sick days they took for the past year are as follows: 12; 4; 15; 3; 11; 8; 6; 8. Let x = the
number of sick days they took for the past year. Should the personnel team believe that the mean
number is about 10?
Exercise 9.16.9
(Solution on p. 425.)
In 1955, Life Magazine reported that the 25 year-old mother of three worked, on average, an 80
hour week. Recently, many groups have been studying whether or not the women’s movement
has, in fact, resulted in an increase in the average work week for women (combining employment
and at-home work). Suppose a study was done to determine if the mean work week has increased.
81 women were surveyed with the following results. The sample mean was 83; the sample stan-
dard deviation was 10. Does it appear that the mean work week has increased for women at the
5% level?
Exercise 9.16.10
Your statistics instructor claims that 60 percent of the students who take her Elementary Statistics
class go through life feeling more enriched. For some reason that she can’t quite figure out, most
people don’t believe her. You decide to check this out on your own. You randomly survey 64 of
her past Elementary Statistics students and find that 34 feel more enriched as a result of her class.
Now, what do you think?
Exercise 9.16.11
(Solution on p. 425.)
A Nissan Motor Corporation advertisement read, “The average man’s I.Q. is 107. The average
brown trout’s I.Q. is 4. So why can’t man catch brown trout?” Suppose you believe that the brown
trout’s mean I.Q. is greater than 4. You catch 12 brown trout. A fish psychologist determines the
I.Q.s as follows: 5; 4; 7; 3; 6; 4; 5; 3; 6; 3; 8; 5. Conduct a hypothesis test of your belief.
Exercise 9.16.12
Refer to the previous problem. Conduct a hypothesis test to see if your decision and conclusion
would change if your belief were that the brown trout’s mean I.Q. is not 4.
Exercise 9.16.13
(Solution on p. 425.)
According to an article in Newsweek, the natural ratio of girls to boys is 100:105. In China, the
birth ratio is 100: 114 (46.7% girls). Suppose you don’t believe the reported figures of the percent
of girls born in China. You conduct a study. In this study, you count the number of girls and boys
born in 150 randomly chosen recent births. There are 60 girls and 90 boys born of the 150. Based
on your study, do you believe that the percent of girls born in China is 46.7?
Exercise 9.16.14
A poll done for Newsweek found that 13% of Americans have seen or sensed the presence of an
angel. A contingent doubts that the percent is really that high. It conducts its own survey. Out
of 76 Americans surveyed, only 2 had seen or sensed the presence of an angel. As a result of the
Available for free at Connexions <http://cnx.org/content/col10522/1.40>
405
contingent’s survey, would you agree with the Newsweek poll? In complete sentences, also give
three reasons why the two polls might give different results.
Exercise 9.16.15
(Solution on p. 425.)
The mean work week for engineers in a start-up company is believed to be about 60 hours. A
newly hired engineer hopes that it’s shorter. She asks 10 engineering friends in start-ups for the
lengths of their mean work weeks. Based on the results that follow, should she count on the mean
work week to be shorter than 60 hours?
Data (length of mean work week): 70; 45; 55; 60; 65; 55; 55; 60; 50; 55.
Exercise 9.16.16
Use the “Lap time” data for Lap 4 (see Table of Contents) to test the claim that Terri finishes Lap
4, on average, in less than 129 seconds. Use all twenty races given.
Exercise 9.16.17
Use the “Initial Public Offering” data (see Table of Contents) to test the claim that the mean offer
price was $18 per share. Do not use all the data. Use your random number generator to randomly
survey 15 prices.
NOTE: The following questions were written by past students. They are excellent problems!
Exercise 9.16.18
18. "Asian Family Reunion" by Chau Nguyen
❊✈❡r② t✇♦ ②❡❛rs ✐t ❝♦♠❡s ❛r♦✉♥❞
❲❡ ❛❧❧ ❣❡t t♦❣❡t❤❡r ❢r♦♠ ❞✐❢❢❡r❡♥t t♦✇♥s✳
■♥ ♠② ❤♦♥❡st ♦♣✐♥✐♦♥
■t✬s ♥♦t ❛ t②♣✐❝❛❧ ❢❛♠✐❧② r❡✉♥✐♦♥
◆♦t ❢♦rt②✱ ♦r ❢✐❢t②✱ ♦r s✐①t②✱
❇✉t ❤♦✇ ❛❜♦✉t s❡✈❡♥t② ❝♦♠♣❛♥✐♦♥s✦
❚❤❡ ❦✐❞s ✇♦✉❧❞ ♣❧❛②✱ s❝r❡❛♠✱ ❛♥❞ s❤♦✉t
❖♥❡ ♠✐♥✉t❡ t❤❡②✬r❡ ❤❛♣♣②✱ ❛♥♦t❤❡r t❤❡②✬❧❧ ♣♦✉t✳
❚❤❡ t❡❡♥❛❣❡rs ✇♦✉❧❞ ❧♦♦❦✱ st❛r❡✱ ❛♥❞ ❝♦♠♣❛r❡
❋r♦♠ ❤♦✇ t❤❡② ❧♦♦❦ t♦ ✇❤❛t t❤❡② ✇❡❛r✳
❚❤❡ ♠❡♥ ✇♦✉❧❞ ❝❤❛t ❛❜♦✉t t❤❡✐r ❜✉s✐♥❡ss
❚❤❛t t❤❡② ♠❛❦❡ ♠♦r❡✱ ❜✉t ♥❡✈❡r ❧❡ss✳
▼♦♥❡② ✐s ❛❧✇❛②s t❤❡✐r s✉❜❥❡❝t
❆♥❞ t❤❡r❡✬s ❛❧✇❛②s t❛❧❦ ♦❢ ♠♦r❡ ♥❡✇ ♣r♦❥❡❝ts✳
❚❤❡ ✇♦♠❡♥ ❣❡t t✐r❡❞ ❢r♦♠ ❛❧❧ ♦❢ t❤❡ ❝❤❛ts
❚❤❡② ❤❡❛❞ t♦ t❤❡ ❦✐t❝❤❡♥ t♦ s❡t ♦✉t t❤❡ ♠❛ts✳
❙♦♠❡ ✇♦✉❧❞ s✐t ❛♥❞ s♦♠❡ ✇♦✉❧❞ st❛♥❞
❊❛t✐♥❣ ❛♥❞ t❛❧❦✐♥❣ ✇✐t❤ ♣❧❛t❡s ✐♥ t❤❡✐r ❤❛♥❞s✳
❚❤❡♥ ❝♦♠❡ t❤❡ ❣❛♠❡s ❛♥❞ t❤❡ s♦♥❣s
❆♥❞ s✉❞❞❡♥❧②✱ ❡✈❡r②♦♥❡ ❣❡ts ❛❧♦♥❣✦
❲✐t❤ ❛❧❧ t❤❛t ❧❛✉❣❤t❡r✱ ✐t✬s s❛❞ t♦ s❛②
❚❤❛t ✐t ❛❧✇❛②s ❡♥❞s ✐♥ t❤❡ s❛♠❡ ♦❧❞ ✇❛②✳
❚❤❡② ❤✉❣ ❛♥❞ ❦✐ss ❛♥❞ s❛② ✧❣♦♦❞✲❜②❡✧
❆♥❞ t❤❡♥ t❤❡② ❛❧❧ ❜❡❣✐♥ t♦ ❝r②✦
■ s❛② t❤❛t ✻✵ ♣❡r❝❡♥t s❤❡❞ t❤❡✐r t❡❛rs
❇✉t ♠② ♠♦♠ ❝♦✉♥t❡❞ ✸✺ ♣❡♦♣❧❡ t❤✐s ②❡❛r✳
❙❤❡ s❛✐❞ t❤❛t ❜♦②s ❛♥❞ ♠❡♥ ✇✐❧❧ ❛❧✇❛②s ❤❛✈❡ t❤❡✐r ♣r✐❞❡✱
❙♦ ✇❡ ✇♦♥✬t ❡✈❡r s❡❡ t❤❡♠ ❝r②✳
■ ♠②s❡❧❢ ❞♦♥✬t t❤✐♥❦ s❤❡✬s ❝♦rr❡❝t✱
Available for free at Connexions <http://cnx.org/content/col10522/1.40>
CHAPTER 9. HYPOTHESIS TESTING: SINGLE MEAN AND SINGLE
406
PROPORTION
❙♦ ❝♦✉❧❞ ②♦✉ ♣❧❡❛s❡ tr② t❤✐s ♣r♦❜❧❡♠ t♦ s❡❡ ✐❢ ②♦✉ ♦❜❥❡❝t❄
Exercise 9.16.19
(Solution on p. 425.)
"The Problem with Angels" by Cyndy Dowling
❆❧t❤♦✉❣❤ t❤✐s ♣r♦❜❧❡♠ ✐s ✇❤♦❧❧② ♠✐♥❡✱
❚❤❡ ❝❛t❛❧②st ❝❛♠❡ ❢r♦♠ t❤❡ ♠❛❣❛③✐♥❡✱ ❚✐♠❡✳
❖♥ t❤❡ ♠❛❣❛③✐♥❡ ❝♦✈❡r ■ ❞✐❞ ❢✐♥❞
❚❤❡ r❡❛❧♠ ♦❢ ❛♥❣❡❧s t✐❝❦❧✐♥❣ ♠② ♠✐♥❞✳
■♥s✐❞❡✱ ✻✾✪ ■ ❢♦✉♥❞ t♦ ❜❡
■♥ ❛♥❣❡❧s✱ ❆♠❡r✐❝❛♥s ❞♦ ❜❡❧✐❡✈❡✳
❚❤❡♥✱ ✐t ✇❛s t✐♠❡ t♦ r✐s❡ t♦ t❤❡ t❛s❦✱
◆✐♥❡t②✲❢✐✈❡ ❤✐❣❤ s❝❤♦♦❧ ❛♥❞ ❝♦❧❧❡❣❡ st✉❞❡♥ts ■ ❞✐❞ ❛s❦✳
❱✐❡✇✐♥❣ ❛❧❧ ❛s ♦♥❡ ❣r♦✉♣✱
❘❛♥❞♦♠ s❛♠♣❧✐♥❣ t♦ ❣❡t t❤❡ s❝♦♦♣✳
❙♦✱ ■ ❛s❦❡❞ ❡❛❝❤ t♦ ❜❡ tr✉❡✱
✧❉♦ ②♦✉ ❜❡❧✐❡✈❡ ✐♥ ❛♥❣❡❧s❄✧ ❚❡❧❧ ♠❡✱ ❞♦✦
❍②♣♦t❤❡s✐③✐♥❣ ❛t t❤❡ st❛rt✱
❚♦t❛❧❧② ❜❡❧✐❡✈✐♥❣ ✐♥ ♠② ❤❡❛rt
❚❤❛t t❤❡ ♣r♦♣♦rt✐♦♥ ✇❤♦ s❛✐❞ ②❡s
❲♦✉❧❞ ❜❡ ❡q✉❛❧ ♦♥ t❤✐s t❡st✳
▲♦ ❛♥❞ ❜❡❤♦❧❞✱ s❡✈❡♥t②✲t❤r❡❡ ❞✐❞ ❛rr✐✈❡✱
❖✉t ♦❢ t❤❡ s❛♠♣❧❡ ♦❢ ♥✐♥❡t②✲❢✐✈❡✳
◆♦✇ ②♦✉r ❥♦❜ ❤❛s ❥✉st ❜❡❣✉♥✱
❙♦❧✈❡ t❤✐s ♣r♦❜❧❡♠ ❛♥❞ ❤❛✈❡ s♦♠❡ ❢✉♥✳
Exercise 9.16.20
"Blowing Bubbles" by Sondra Prull
❙t✉❞②✐♥❣ st❛ts ❥✉st ♠❛❞❡ ♠❡ t❡♥s❡✱
■ ❤❛❞ t♦ ❢✐♥❞ s♦♠❡ s❛♥❡ ❞❡❢❡♥s❡✳
❙♦♠❡ ❧✐❣❤t ❛♥❞ ❧✐❢t✐♥❣ s✐♠♣❧❡ ♣❧❛②
❚♦ ❢❧♦❛t ♠② ♠❛t❤ ❛♥①✐❡t② ❛✇❛②✳
❇❧♦✇✐♥❣ ❜✉❜❜❧❡s ❧✐❢ts ♠❡ ❤✐❣❤
❚❛❦❡s ♠② tr♦✉❜❧❡s t♦ t❤❡ s❦②✳
P❖■❑✦ ❚❤❡②✬r❡ ❣♦♥❡✱ ✇✐t❤ ❛❧❧ ♠② str❡ss
❇✉❜❜❧❡ t❤❡r❛♣② ✐s t❤❡ ❜❡st✳
❚❤❡ ❧❛❜❡❧ s❛✐❞ ❡❛❝❤ t✐♠❡ ■ ❜❧❡✇
❚❤❡ ❛✈❡r❛❣❡ ♥✉♠❜❡r ♦❢ ❜✉❜❜❧❡s ✇♦✉❧❞ ❜❡ ❛t ❧❡❛st ✷✷✳
■ ❜❧❡✇ ❛♥❞ ❜❧❡✇ ❛♥❞ t❤✐s ■ ❢♦✉♥❞
❋r♦♠ ✻✹ ❜❧♦✇s✱ t❤❡② ❛❧❧ ❛r❡ r♦✉♥❞✦
Available for free at Connexions <http://cnx.org/content/col10522/1.40>
407
❇✉t t❤❡ ♥✉♠❜❡r ♦❢ ❜✉❜❜❧❡s ✐♥ ✻✹ ❜❧♦✇s
❱❛r✐❡❞ ✇✐❞❡❧②✱ t❤✐s ■ ❦♥♦✇✳
✷✵ ♣❡r ❜❧♦✇ ❜❡❝❛♠❡ t❤❡ ♠❡❛♥
❚❤❡② ❞❡✈✐❛t❡❞ ❜② ✻✱ ❛♥❞ ♥♦t ✶✻✳
❋r♦♠ ❝♦✉♥t✐♥❣ ❜✉❜❜❧❡s✱ ■ s✉r❡ ❞✐❞ r❡❧❛①
❇✉t ♥♦✇ ■ ❣✐✈❡ t♦ ②♦✉ ②♦✉r t❛s❦✳
❲❛s ✷✷ ❛ r❡❛s♦♥❛❜❧❡ ❣✉❡ss❄
❋✐♥❞ t❤❡ ❛♥s✇❡r ❛♥❞ ♣❛ss t❤✐s t❡st✦
Exercise 9.16.21
(Solution on p. 426.)
21. "Dalmatian Darnation" by Kathy Sparling
❆ ❣r❡❡❞② ❞♦❣ ❜r❡❡❞❡r ♥❛♠❡❞ ❙♣r❡❝❦❧❡s
❇r❡❞ ♣✉♣♣✐❡s ✇✐t❤ ♥✉♠❡r♦✉s ❢r❡❝❦❧❡s
❚❤❡ ❉❛❧♠❛t✐❛♥s ❤❡ s♦✉❣❤t
P♦ss❡ss❡❞ s♣♦t ✉♣♦♥ s♣♦t
❚❤❡ ♠♦r❡ s♣♦ts✱ ❤❡ t❤♦✉❣❤t✱ t❤❡ ♠♦r❡ s❤❡❦❡❧s✳
❍✐s ❝♦♠♣❡t✐t♦rs ❞✐❞ ♥♦t ❛❣r❡❡
❚❤❛t ❢r❡❝❦❧❡s ✇♦✉❧❞ ✐♥❝r❡❛s❡ t❤❡ ❢❡❡✳
❚❤❡② s❛✐❞✱ ❵❵❙♣♦ts ❛r❡ q✉✐t❡ ♥✐❝❡
❇✉t t❤❡② ❞♦♥✬t ❛❢❢❡❝t ♣r✐❝❡❀
❖♥❡ s❤♦✉❧❞ ❜r❡❡❞ ❢♦r ✐♠♣r♦✈❡❞ ♣❡❞✐❣r❡❡✳✬✬
❚❤❡ ❜r❡❡❞❡rs ❞❡❝✐❞❡❞ t♦ ♣r♦✈❡
❚❤✐s str❛t❡❣② ✇❛s ❛ ✇r♦♥❣ ♠♦✈❡✳
❇r❡❡❞✐♥❣ ♦♥❧② ❢♦r s♣♦ts
❲♦✉❧❞ ✇r❡❛❦ ❤❛✈♦❝✱ t❤❡② t❤♦✉❣❤t✳
❍✐s t❤❡♦r② t❤❡② ✇❛♥t t♦ ❞✐s♣r♦✈❡✳
❚❤❡② ♣r♦♣♦s❡❞ ❛ ❝♦♥t❡st t♦ ❙♣r❡❝❦❧❡s
❈♦♠♣❛r✐♥❣ ❞♦❣ ♣r✐❝❡s t♦ ❢r❡❝❦❧❡s✳
■♥ r❡❝♦r❞s t❤❡② ❧♦♦❦❡❞ ✉♣
❖♥❡ ❤✉♥❞r❡❞ ♦♥❡ ♣✉♣s✿
❉❛❧♠❛t✐❛♥s t❤❛t ❢❡t❝❤❡❞ t❤❡ ♠♦st s❤❡❦❡❧s✳
❚❤❡② ❛s❦❡❞ ▼r✳ ❙♣r❡❝❦❧❡s t♦ ♥❛♠❡
❆♥ ❛✈❡r❛❣❡ s♣♦t ❝♦✉♥t ❤❡✬❞ ❝❧❛✐♠
❚♦ ❜r✐♥❣ ✐♥ ❜✐❣ ❜✉❝❦s✳
❙❛✐❞ ❙♣r❡❝❦❧❡s✱ ❵❵❲❡❧❧✱ s❤✉❝❦s✱
■t✬s ❢♦r ♦♥❡ ❤✉♥❞r❡❞ ♦♥❡ t❤❛t ■ ❛✐♠✳✬✬
❙❛✐❞ ❛♥ ❛♠❛t❡✉r st❛t✐st✐❝✐❛♥
❲❤♦ ✇❛♥t❡❞ t♦ ❤❡❧♣ ✇✐t❤ t❤✐s ♠✐ss✐♦♥✳
❵❵❚✇❡♥t②✲♦♥❡ ❢♦r t❤❡ s❛♠♣❧❡
❙t❛♥❞❛r❞ ❞❡✈✐❛t✐♦♥✬s ❛♠♣❧❡✿
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PROPORTION
❚❤❡② ❡①❛♠✐♥❡❞ ♦♥❡ ❤✉♥❞r❡❞ ❛♥❞ ♦♥❡
❉❛❧♠❛t✐❛♥s t❤❛t ❢❡t❝❤❡❞ ❛ ❣♦♦❞ s✉♠✳
❚❤❡② ❝♦✉♥t❡❞ ❡❛❝❤ s♣♦t✱
▼❛r❦✱ ❢r❡❝❦❧❡ ❛♥❞ ❞♦t
❆♥❞ t❛❧❧✐❡❞ ✉♣ ❡✈❡r② ♦♥❡✳
■♥st❡❛❞ ♦❢ ♦♥❡ ❤✉♥❞r❡❞ ♦♥❡ s♣♦ts
❚❤❡② ❛✈❡r❛❣❡❞ ♥✐♥❡t② s✐① ❞♦ts
❈❛♥ t❤❡② ♠✉③③❧❡ ❙♣r❡❝❦❧❡s✬
❖❜s❡ss✐♦♥ ✇✐t❤ ❢r❡❝❦❧❡s
❇❛s❡❞ ♦♥ ❛❧❧ t❤❡ ❞♦❣ ❞❛t❛ t❤❡②✬✈❡ ❣♦t❄
Exercise 9.16.22
"Macaroni and Cheese, please!!" by Nedda Misherghi and Rachelle Hall
As a poor starving student I don’t have much money to spend for even the bare necessities. So
my favorite and main staple food is macaroni and cheese. It’s high in taste and low in cost and
nutritional value.
One day, as I sat down to determine the meaning of life, I got a serious craving for this, oh, so
important, food of my life. So I went down the street to Greatway to get a box of macaroni and
cheese, but it was SO expensive! $2.02 !!! Can you believe it? It made me stop and think. The
world is changing fast. I had thought that the mean cost of a box (the normal size, not some super-
gigantic-family-value-pack) was at most $1, but now I wasn’t so sure. However, I was determined
to find out. I went to 53 of the closest grocery stores and surveyed the prices of macaroni and
cheese. Here are the data I wrote in my notebook:
Price per box of Mac and Cheese:
• 5 stores @ $2.02
• 15 stores @ $0.25
• 3 stores @ $1.29
• 6 stores @ $0.35
• 4 stores @ $2.27
• 7 stores @ $1.50
• 5 stores @ $1.89
• 8 stores @ 0.75.
I could see that the costs varied but I had to sit down to figure out whether or not I was right. If
it does turn out that this mouth-watering dish is at most $1, then I’ll throw a big cheesy party in
our next statistics lab, with enough macaroni and cheese for just me. (After all, as a poor starving
student I can’t be expected to feed our class of animals!)
Exercise 9.16.23
(Solution on p. 426.)
"William Shakespeare: The Tragedy of Hamlet, Prince of Denmark" by Jacqueline Ghodsi
THE CHARACTERS (in order of appearance):
• HAMLET, Prince of Denmark and student of Statistics
• POLONIUS, Hamlet’s tutor
• HOROTIO, friend to Hamlet and fellow student
Scene: The great library of the castle, in which Hamlet does his lessons
Act I
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409
(The day is fair, but the face of Hamlet is clouded. He paces the large room. His tutor, Polonius, is
reprimanding Hamlet regarding the latter’s recent experience. Horatio is seated at the large table
at right stage.)
POLONIUS: My Lord, how cans’t thou admit that thou hast seen a ghost! It is but a figment of
your imagination!
HAMLET: I beg to differ; I know of a certainty that five-and-seventy in one hundred of us, con-
demned to the whips and scorns of time as we are, have gazed upon a spirit of health, or goblin
damn’d, be their intents wicked or charitable.
POLONIUS If thou doest insist upon thy wretched vision then let me invest your time; be true
to thy work and speak to me through the reason of the null and alternate hypotheses. (He turns
to Horatio.) Did not Hamlet himself say, “What piece of work is man, how noble in reason, how
infinite in faculties? Then let not this foolishness persist. Go, Horatio, make a survey of three-and-
sixty and discover what the true proportion be. For my part, I will never succumb to this fantasy,
but deem man to be devoid of all reason should thy proposal of at least five-and-seventy in one
hundred hold true.
HORATIO (to Hamlet): What should we do, my Lord?
HAMLET: Go to thy purpose, Horatio.
HORATIO: To what end, my Lord?
HAMLET: That you must teach me. But let me conjure you by the rights of our fellowship, by the
consonance of our youth, but the obligation of our ever-preserved love, be even and direct with
me, whether I am right or no.
(Horatio exits, followed by Polonius, leaving Hamlet to ponder alone.)
Act II
(The next day, Hamlet awaits anxiously the presence of his friend, Horatio. Polonius enters and
places some books upon the table just a moment before Horatio enters.)
POLONIUS: So, Horatio, what is it thou didst reveal through thy deliberations?
HORATIO: In a random survey, for which purpose thou thyself sent me forth, I did discover that
one-and-forty believe fervently that the spirits of the dead walk with us. Before my God, I might
not this believe, without the sensible and true avouch of mine own eyes.
POLONIUS: Give thine own thoughts no tongue, Horatio. (Polonius turns to Hamlet.) But look
to’t I charge you, my Lord. Come Horatio, let us go together, for this is not our test. (Horatio and
Polonius leave together.)
HAMLET: To reject, or not reject, that is the question: whether ‘tis nobler in the mind to suffer the
slings and arrows of outrageous statistics, or to take arms against a sea of data, and, by opposing,
end them. (Hamlet resignedly attends to his task.)
(Curtain falls)
Exercise 9.16.24
"Untitled" by Stephen Chen
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PROPORTION
I’ve often wondered how software is released and sold to the public. Ironically, I work for a com-
pany that sells products with known problems. Unfortunately, most of the problems are difficult
to create, which makes them difficult to fix. I usually use the test program X, which tests the prod-
uct, to try to create a specific problem. When the test program is run to make an error occur, the
likelihood of generating an error is 1%.
So, armed with this knowledge, I wrote a new test program Y that will generate the same error that
test program X creates, but more often. To find out if my test program is better than the original,
so that I can convince the management that I’m right, I ran my test program to find out how often
I can generate the same error. When I ran my test program 50 times, I generated the error twice.
While this may not seem much better, I think that I can convince the management to use my test
program instead of the original test program. Am I right?
Exercise 9.16.25
(Solution on p. 426.)
Japanese Girls’ Names
by Kumi Furuichi
It used to be very typical for Japanese girls’ names to end with “ko.” (The trend might have
started around my grandmothers’ generation and its peak might have been around my mother’s
generation.) “Ko” means “child” in Chinese character. Parents would name their daughters with
“ko” attaching to other Chinese characters which have meanings that they want their daughters
to become, such as Sachiko – a happy child, Yoshiko – a good child, Yasuko – a healthy child, and
so on.
However, I noticed recently that only two out of nine of my Japanese girlfriends at this school have
names which end with “ko.” More and more, parents seem to have become creative, modernized,
and, sometimes, westernized in naming their children.
I have a feeling that, while 70 percent or more of my mother’s generation would have names with
“ko” at the end, the proportion has dropped among my peers. I wrote down all my Japanese
friends’, ex-classmates’, co-workers, and acquaintances’ names that I could remember. Below are
the names. (Some are repeats.) Test to see if the proportion has dropped for this generation.
Ai, Akemi, Akiko, Ayumi, Chiaki, Chie, Eiko, Eri, Eriko, Fumiko, Harumi, Hitomi, Hiroko, Hi-
roko, Hidemi, Hisako, Hinako, Izumi, Izumi, Junko, Junko, Kana, Kanako, Kanayo, Kayo, Kayoko,
Kazumi, Keiko, Keiko, Kei, Kumi, Kumiko, Kyoko, Kyoko, Madoka, Maho, Mai, Maiko, Maki,
Miki, Miki, Mikiko, Mina, Minako, Miyako, Momoko, Nana, Naoko, Naoko, Naoko, Noriko,
Rieko, Rika, Rika, Rumiko, Rei, Reiko, Reiko, Sachiko, Sachiko, Sachiyo, Saki, Sayaka, Sayoko,
Sayuri, Seiko, Shiho, Shizuka, Sumiko, Takako, Takako, Tomoe, Tomoe, Tomoko, Touko, Yasuko,
Yasuko, Yasuyo, Yoko, Yoko, Yoko, Yoshiko, Yoshiko, Yoshiko, Yuka, Yuki, Yuki, Yukiko, Yuko,
Yuko.
Exercise 9.16.26
Phillip’s Wish by Suzanne Osorio
▼② ♥❡♣❤❡✇ ❧✐❦❡s t♦ ♣❧❛②
❈❤❛s✐♥❣ t❤❡ ❣✐r❧s ♠❛❦❡s ❤✐s ❞❛②✳
❍❡ ❛s❦❡❞ ❤✐s ♠♦t❤❡r
■❢ ✐t ✐s ♦❦❛②
❚♦ ❣❡t ❤✐s ❡❛r ♣✐❡r❝❡❞✳
❙❤❡ s❛✐❞✱ ❵❵◆♦ ✇❛②✦✬✬
❚♦ ♣♦❦❡ ❛ ❤♦❧❡ t❤r♦✉❣❤ ②♦✉r ❡❛r✱
■s ♥♦t ✇❤❛t ■ ✇❛♥t ❢♦r ②♦✉✱ ❞❡❛r✳
❍❡ ❛r❣✉❡❞ ❤✐s ♣♦✐♥t q✉✐t❡ ✇❡❧❧✱
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411
❙❛②s ❡✈❡♥ ♠② ♠❛❝❤♦ ♣❛❧✱ ▼❡❧✱
❍❛s ❣♦tt❡♥ t❤✐s ❞♦♥❡✳
■t✬s ❛❧❧ ❥✉st ❢♦r ❢✉♥✳
❈✬♠♦♥ ♣❧❡❛s❡✱ ♠♦♠✱ ♣❧❡❛s❡✱ ✇❤❛t t❤❡ ❤❡❧❧✳
❆❣❛✐♥ P❤✐❧❧✐♣ ❝♦♠♣❧❛✐♥❡❞ t♦ ❤✐s ♠♦t❤❡r✱
❙❛②✐♥❣ ❤❛❧❢ ❤✐s ❢r✐❡♥❞s ✭✐♥❝❧✉❞✐♥❣ t❤❡✐r ❜r♦t❤❡rs✮
❆r❡ ♣✐❡r❝✐♥❣ t❤❡✐r ❡❛rs
❆♥❞ t❤❡② ❤❛✈❡ ♥♦ ❢❡❛rs
❍❡ ✇❛♥ts t♦ ❜❡ ❧✐❦❡ t❤❡ ♦t❤❡rs✳
❙❤❡ s❛✐❞✱ ❵❵■ t❤✐♥❦ ✐t✬s ♠✉❝❤ ❧❡ss✳
❲❡ ♠✉st ❞♦ ❛ ❤②♣♦t❤❡s✐s t❡st✳
❆♥❞ ✐❢ ②♦✉ ❛r❡ r✐❣❤t✱
■ ✇♦♥✬t ♣✉t ✉♣ ❛ ❢✐❣❤t✳
❇✉t✱ ✐❢ ♥♦t✱ t❤❡♥ ♠② ❝❛s❡ ✇✐❧❧ r❡st✳✬✬
❲❡ ♣r♦❝❡❡❞❡❞ t♦ ❝❛❧❧ ❢✐❢t② ❣✉②s
❚♦ s❡❡ ✇❤♦s❡ ♣r❡❞✐❝t✐♦♥ ✇♦✉❧❞ ❢❧②✳
◆✐♥❡t❡❡♥ ♦❢ t❤❡ ❢✐❢t②
❙❛✐❞ ♣✐❡r❝✐♥❣ ✇❛s ♥✐❢t②
❆♥❞ ❡❛rr✐♥❣s t❤❡②✬❞ ♦❝❝❛s✐♦♥❛?