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Math 221/Questions& verifiedAnswers/ Already
Graded A+ 2025
From a random sample of 58 businesses, it is found that the mean time the owner
spends on administrative issues each week is 21.69 with a population standard
deviation of 3.23. What is the 95% confidence interval for the amount of time
spent on administrative issues?
A. (19.24, 24.14)
B. (21.78, 22.60)
C. (20.86, 22.52)
D. (20.71, 22.67) - (answer)C. (20.86, 22.52)
If a confidence interval is given from 45.82 up to 55.90 and the mean is known to
be 50.86, what is the margin of error?
2.52
5.04
45.82
10.08 - (answer)5.04
If a computer manufacturer needed a supplier that could produce parts that were
very precise, what characteristics would be better?
narrow confidence interval at low confidence level
narrow confidence interval at high confidence level
wide confidence interval with high confidence level
, 2
wide confidence interval with low confidence level - (answer)narrow confidence
interval at high confidence level
Which of the following are most likely to lead to a wide confidence interval?
small standard deviation
small sample size
large mean
large sample size - (answer)small sample size
If you were designing a study that would benefit from data points with high
values, you would want the input variable to have:
a large sample size
a large mean
a large standard deviation
a large margin of error - (answer)a large mean
The 95% confidence interval for these parts is 56.98 to 57.05 under normal
operations. A systematic sample is taken from the manufacturing line to
determine if the production process is still within acceptable levels. The mean of
the sample is 56.99. What should be done about the production line?
Keep the line operating as it is inside the confidence interval
Stop the line as it is inside the confidence interval
Stop the line as it is outside the confidence interval
, 3
Keep the line operating as it is outside the confidence interval - (answer)Keep the
line operating as it is inside the confidence interval
In a sample of 57 temperature readings taken from the freezer of a restaurant,
the mean is 29.6 degrees and the population standard deviation is 2.7 degrees.
What would be the 80% confidence interval for the temperatures in the freezer?
(31.90, 32.44)
(29.14, 30.06)
(24.25, 35.05)
(26.91, 32.31) - (answer)(29.14, 30.06)
What is the 99% confidence interval for a sample of 36 seat belts that have a
mean length of 85.6 inches long and a population standard deviation of 2.5
inches?
(80.6, 90.6)
(83.1, 88.1)
(84.4, 86.8)
(84.5, 86.7) - (answer)(84.5, 86.7)
If two samples A and B had the same mean and standard deviation, but sample A
had a larger sample size, which sample would have the wider 95% confidence
interval?
Sample B as its sample is more dispersed
Sample B as it has the smaller sample
Math 221/Questions& verifiedAnswers/ Already
Graded A+ 2025
From a random sample of 58 businesses, it is found that the mean time the owner
spends on administrative issues each week is 21.69 with a population standard
deviation of 3.23. What is the 95% confidence interval for the amount of time
spent on administrative issues?
A. (19.24, 24.14)
B. (21.78, 22.60)
C. (20.86, 22.52)
D. (20.71, 22.67) - (answer)C. (20.86, 22.52)
If a confidence interval is given from 45.82 up to 55.90 and the mean is known to
be 50.86, what is the margin of error?
2.52
5.04
45.82
10.08 - (answer)5.04
If a computer manufacturer needed a supplier that could produce parts that were
very precise, what characteristics would be better?
narrow confidence interval at low confidence level
narrow confidence interval at high confidence level
wide confidence interval with high confidence level
, 2
wide confidence interval with low confidence level - (answer)narrow confidence
interval at high confidence level
Which of the following are most likely to lead to a wide confidence interval?
small standard deviation
small sample size
large mean
large sample size - (answer)small sample size
If you were designing a study that would benefit from data points with high
values, you would want the input variable to have:
a large sample size
a large mean
a large standard deviation
a large margin of error - (answer)a large mean
The 95% confidence interval for these parts is 56.98 to 57.05 under normal
operations. A systematic sample is taken from the manufacturing line to
determine if the production process is still within acceptable levels. The mean of
the sample is 56.99. What should be done about the production line?
Keep the line operating as it is inside the confidence interval
Stop the line as it is inside the confidence interval
Stop the line as it is outside the confidence interval
, 3
Keep the line operating as it is outside the confidence interval - (answer)Keep the
line operating as it is inside the confidence interval
In a sample of 57 temperature readings taken from the freezer of a restaurant,
the mean is 29.6 degrees and the population standard deviation is 2.7 degrees.
What would be the 80% confidence interval for the temperatures in the freezer?
(31.90, 32.44)
(29.14, 30.06)
(24.25, 35.05)
(26.91, 32.31) - (answer)(29.14, 30.06)
What is the 99% confidence interval for a sample of 36 seat belts that have a
mean length of 85.6 inches long and a population standard deviation of 2.5
inches?
(80.6, 90.6)
(83.1, 88.1)
(84.4, 86.8)
(84.5, 86.7) - (answer)(84.5, 86.7)
If two samples A and B had the same mean and standard deviation, but sample A
had a larger sample size, which sample would have the wider 95% confidence
interval?
Sample B as its sample is more dispersed
Sample B as it has the smaller sample
