Sagot :
Answer:
(d) Inferential. (e) Descriptive. (f) Descriptive.
1.2 (a) Descriptive. (b) Inferential. (c) Descriptive.
(d) Inferential. (e) Descriptive.
1.3 (a) Open heart patients operated on in the last
year. (b) 30 patients selected. (c) Length of stay.
1.4 (a) People who wear T-shirts. (b) 50 people
selected. (c) Whether they cut off the tag or not.
1.5 Population: employees at Citigroup Inc. Sample:
35 employees selected.
1.6 Population: Texas residents. Sample: 500 people
from Texas selected.
1.7 Population: 10,000 families affected by the flood.
Sample: 75 affected families selected.
1.8 (a) Population: All people who purchase a dining
room table. Sample: 5 people selected at random.
Probability question. (b) Population: All people
entering the rest area and food court. Sample: 25
people selected. Statistics question. (c) Population:
All people who use the slide. Sample: 50 people
selected at random. Probability question.
(d) Population: All doors that open automatically.
Sample: 100 doors selected. Statistics question.
(e) Population: All people entering LAX. Sample:
1000 people selected. Statistics question.
(f) Population: All women. Sample: 34 selected.
Probability question. (g) Population: Two populations
- two types of nursing homes. Sample: Several nursing
homes selected. Statistics question.
1.9 (a) Population: all cheddar cheeses. Sample: 20
cheddar cheeses selected. (b) Probability question:
What is the probability at least 10 of the cheddar
cheeses selected are aged less than two years?
Statistics questions: Suppose 12 of the cheddar cheeses
selected are aged less than two years. Does this
suggest that the true proportion of all cheddars aged
less than two years has decreased?
1.10 (a) Population: All television households in the
United States. Sample: 500 TV households selected.
(b) Probability question: What is the probability at
most 400 of the TV households selected have at least
one DVD player? Statistics question: Estimate the
true proportion of TV households that have at least
one DVD player.
1.11 (a) Population: All Americans. (b) Sample:
1000 Americans selected. (c) Variable: Whether or not
each believes sharks are dangerous.
1.12 (a) Population: All American companies.
(b) Sample: 75 companies selected. (c) Variable:
Whether each company has overseas IT workers.
(d) Probability question: What is the probability
exactly 30 of the 75 companies selected have overseas
IT workers? Statistics question: Use the resulting data
to determine if there is evidence the proportion of
companies with overseas IT workers has changed.
1.13 Population: All shampoos. Sample: 20 shampoos
selected. Variable: Amount of sulfur in each shampoo.
1.14 Population: People diagnosed with hepatitis C.
Sample: 50 patients selected. Variable: Liver enzyme
levels.
1.15 (a) Population: All Bounty paper towel rolls.
(b) Sample: 35 rolls selected. (c) Variable: Amount of
absorption.
Section 1.3
1.16 (a) Observational study. (b) Sample: The
students who respond to the questions. (c) Not a
random sample, only one dorm.
1.17 (a) Observational study. (b) Sample: 25
volunteer fire companies selected. (c) Not a random
sample, largest companies selected.
1.18 (a) Population: All 12-ounce bottles of soda.
Sample: The bottles selected. (b) Yes, a simple
random sample.
1.19 Assign a number to each shipped weather
station. Select numbers using a random number
generator and examine each weather station
corresponding to the numbers selected.
1.20 (a) Observational study. (b) Population: All
Massachusetts State Police. Sample: 12 officers
selected. (c) Not a random sample, only 1 shift
considered.
1.21 (a) Population: All men who use a disposable
razor. Sample: 100 men selected. (b) Not a random
sample. Just selected men observed buying a razor.
1.22 Obtain a list of people who have purchased this
product, and assign a number to each person.
Randomly select numbers from a random number
table or random number generator, and ask each
corresponding customer how long it took to set up the
fence.
2
1.23 Assign a number to each challenge. Randomly
select numbers from a random number table or
random number generator.
1.24 (a) Assign a number to each mile-long stretch.
proportion of other components. (c) Randomly select
stores from around the country that sell comforters.
Visit the selected stores, and randomly purchase
comforters on display.
2.4 (a) Numerical, discrete. (b) Numerical