Download Question 1 4 points Save A study of 200 apple trees showed that the

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Question 1
4 points
A study of 200 apple trees showed that the average number of
apples per tree was 500. The standard deviation of the population
is 200. Which of the following is the 98% confidence interval for
the mean number of apples for all trees?
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(472.3, 527.7)
(467.1, 532.9)
(463.8, 536.2)
(463.6, 536.4)
Question 2
4 points
A study of 50 white mice showed that their average weight was
6.2 ounces. The standard deviation of the population is 0.4
ounces. Which of the following is the 90% confidence interval for
the mean weight per white mouse?
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(6.11, 6.29)
(5.98, 6.42)
(6.09, 6.31)
(5.54, 6.86)
Question 3
4 points
A study of 90 bolts of carpet showed that their average length was
200 yards. The standard deviation of the population is 6 yards.
Which of the following is the 95% confidence interval for the mean
length per bolt of carpet?
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(198.96, 201.04)
(197.06, 202.94)
(198.53, 201.47)
(198.76, 201.24)
Question 4
4 points
If a population has standard deviation 14, what is the minimum
sample size to be 95% confident that the error should be accurate
to within 5?
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61
6
31
12
Question 5
4 points
A researcher conducted a study of the access speed of 30 hard
drives and concluded that his maximum error of estimate was 20.
If he were to conduct a second study to reduce the maximum error
of estimate to 4, about how many hard drives should he include in
his new sample?
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30
60
150
750
Question 6
4 points
A study of peach trees showed that the average number of
peaches per tree was 500. The standard deviation of the
population is 200. A scientist wishes to find the 95% confidence
interval for the mean number of peaches per tree. How many
trees does she need to sample to be accurate within 14 peaches
per tree?
Save
205
553
658
784
Question 7
4 points
A study of elephants wishes to determine the average weight of a
certain subspecies of elephants. The standard deviation of the
population is 1500 pounds. How many elephants need to be
weighed so find we can be 90% confident to be accurate within
350 pounds?
50
60
71
Save
166
Question 8
4 points
A previous study of nickels showed that the standard deviation of
the weight of nickels is 200 milligrams. A coin counter
manufacturer wishes to find the 80% confidence interval for the
average weight of a nickel. How many nickels does he need to
weigh to be accurate within 10 milligrams?
Save
400
657
1083
284
Question 9
4 points
A previous analysis of paper boxes showed that the standard
deviation of their lengths is 7 millimeters. A packer wishes to find
the 99% confidence interval for the average length of a box. How
many boxes does he need to measure to be accurate within 4
millimeters?
Save
4
30
21
17
Question 10
4 points
Save
In a study of size 8 where the variance is unknown, the
distribution that should be used to calculate confidence intervals
is
a normal distribution
a t distribution with 7 degrees of freedom
a t distribution with 8 degrees of freedom
a t distribution with 9 degrees of freedom
Question 11
4 points
A food snack manufacturer samples 13 bags of pretzels off the
assembly line and weighed their contents. If the sample mean is
9.8 and the sample standard deviation is 0.15, find the 95%
confidence interval of the true mean.
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(9.76, 9.84)
(9.47, 10.13)
(9.72, 9.88)
(9.71, 9.89)
Question 12
4 points
8 squirrels were found to have an average weight of 9.8 ounces
with a sample standard deviation is 0.10. Find the 95%
confidence interval of the true mean weight.
Save
(9.69, 9.91)
(9.48, 10.12)
(9.71, 9.89)
(9.76, 9.84)
Question 13
4 points
The winning team's scores in 7 high school basketball games
were recorded. If the sample mean is 10.2 points and the sample
standard deviation is 0.25 points, find the 98% confidence
interval of the true mean.
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(10.11, 10.29)
(9.90, 10.50)
(9.98, 10.42)
(9.61, 10.79)
Question 14
4 points
A recent study of 750 Internet users in Europe found that 35% of
Internet users were women. What is the 95% confidence interval
of the true proportion of women in Europe who use the Internet?
Save
0.321<p<0.379
0.316<p<0.384
0.309<p<0.391
0.305<p<0.395
Question 15
4 points
A survey of 800 women shoppers found that 17% of them shop
on impulse. What is the 98% confidence interval for the true
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proportion of women shoppers who shop on impulse?
0.148<p<0.192
0.136<p<0.204
0.144<p<0.196
0.139<p<0.201
Question 16
4 points
A random sample of 70 voters found that 40% were going to vote
for a certain candidate. Find the 95% limit for the population
proportion of voters who will vote for that candidate.
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28.5% < p < 51.5%
29.4% < p < 50.6%
30.4% < p < 49.6%
34.3% < p < 45.7%
Question 17
4 points
A random sample of 95 printers discovered that 15 of them were
being used in small businesses . Find the 99% limit for the
population proportion of printers that are used in small
businesses.
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-0.026 < p < 0.341
0.062 < p < 0.254
0.071 < p < 0.245
0.126 < p < 0.190
Question 18
4 points
In a sample of 60 mice, a biologist found that 42% were able to
run a maze in 30 seconds or less. Find the 95% limit for the
population proportion of mice who can run that maze in 30
seconds or less.
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35.8% < p < 48.2%
31.5% < p < 52.5%
29.5% < p < 54.5%
23.3% < p < 60.7%
Question 19
4 points
Save
In a sample of 855 bartenders, 48% heard complaints from
patrons about work. If the margin of error was 4.4%, what was
the confidence level that was used?
90%
95%
98%
99%
Question 20
4 points
A recent poll of 700 people who work indoors found that 278 of
them smoke. If the researchers want to be 98% confident of their
results to within 3.5%, how large a sample is necessary?
Save
751
1062
1301
532
Question 21
4 points
The Academy of Orthopedic Surgeons states that 80% of women
wear shoes that are too small for their feet. A researcher wants
to be 98% confident that this proportion is within 3% of the true
proportion. How large a sample is necessary?
Save
966
683
1183
484
Question 22
4 points
A report states that 40% of home owners had a vegetable
garden. How large a sample is needed to estimate the true
proportion of home owners who have vegetable gardens to
within 6% with 95% confidence?
65
129
257
Save
514
Question 23
4 points
A report states that 42% of home owners had a vegetable
garden. How large a sample is needed to estimate the true
proportion of home owners who have vegetable gardens to
within 5% with 96% confidence?
Save
121
206
242
411
Question 24
4 points
A sample of 1,108 was used to estimate a proportion with 98%
confidence. If , what was the amount of error?
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0.040
0.025
0.035
0.028
Question 25
4 points
John Davis, a manager of a supermarket, wants to estimate the
proportion of customers that will be using food stamps at his
store. How large a sample is required to estimate the true
proportion to within 3% with 98% confidence?
756
1,849
1,067
1,509
1
_3993545_1
_3993545_1
Save