BESC 3010 - TEST 2 COMBINED SET
EXAM QUESTIONS WITH COMPLETE
SOLUTIONS
When the range of confidence for a confidence interval becomes higher - from 80% to
99%, for example - then the confidence interval will... - Answer-Become Wider
Imagine a sample with n = 64 and a mean of 121 that comes from a population with a
standard deviation of 16. Based on these data, what would be the 80% confidence
interval for the population mean? (Use z-scores of ±1.28 for the 80% confidence level.) -
Answer-(118.44, 123.56)
What is the point estimate for the population mean if the population standard deviation
is 10, the sample size is 100, and the sample mean is 80? - Answer-80
For which measures is it possible to compute a confidence interval? - Answer-Any
population parameter
As the standard deviation for a distribution increases, then the corresponding
confidence interval will... - Answer-Become wider
As the mean for a sample becomes greater, the width of the corresponding confidence
interval will... - Answer-Stay the same
Imagine a sample with n = 49 and a mean of 183 that comes from a population with a
standard deviation of 21. Based on these data, what would be the 99.9% confidence
interval for the population mean? (Use z-scores of ±3.29 for the 99.9% confidence
level.) - Answer-(173.13, 192.87)
Imagine a sample with n = 400 and a mean of 68 that comes from a population with a
standard deviation of 20. Based on these data, what would be the 90% confidence
interval for the population mean? (Use z-scores of ±1.64 for the 90% confidence level.) -
Answer-(66.36, 69.64)
A confidence interval specifies a range of values for a parameter estimate, whereas a(n)
_____ specifies just a single value for that parameter. - Answer-Point estimate
Which is generally more precise (in the statistical sense): a point estimate or a
confidence interval? - Answer-A point estimate
, Which is generally more accurate (in the statistical sense): a point estimate or a
confidence interval? - Answer-A confidence interval
A point estimate for the population mean is based on... - Answer-The sample mean
"Estimation" refers to a class of.... - Answer-Inferential statistics
How is the point estimate affected when the sample standard deviation increases? -
Answer-It does not change
Imagine that samples - Sample A with n = 20 and Sample B with n = 200 - are drawn
from the same population and confidence intervals are computed for the same
variables, which sample will likely have the more precise confidence interval? - Answer-
Sample B
How is a confidence interval affected when the sample standard deviation decreases? -
Answer-It becomes narrower
When the range of confidence for a confidence interval becomes lower - from 90% to
80%, for example - then the confidence interval will... - Answer-Become narrower
What is the point estimate for the population mean if the population standard deviation
is 24, the sample size is 36, and the sample mean is 110? - Answer-110
As the mean for a distribution increases, then the width of the corresponding confidence
interval will... - Answer-Stay the same
Imagine a sample with n = 49 and a mean of 60 that comes from a population with a
standard deviation of 7. Based on these data, what would be the 99.9% confidence
interval for the population mean? (Use z-score of +3.29 for the 99.9% confidence level.)
- Answer-(56.71, 63.29)
The sample mean is ________ and a confidence interval for the mean is _______. -
Answer-a descriptive statistic; an inferential statistic
Which is more precise (in the statistical sense): a point estimate or a confidence
interval? - Answer-A point estimate
If a researcher wants to test whether an experimental group is different from the general
population, the she would test... - Answer-the null hypothesis of no difference between
the group and the population.
In a two-tailed or non-directional test, if the critical value has a greater absolute value
than the observed (or test) value does, the the null hypothesis... - Answer-is not rejected
(i.e., retained).
EXAM QUESTIONS WITH COMPLETE
SOLUTIONS
When the range of confidence for a confidence interval becomes higher - from 80% to
99%, for example - then the confidence interval will... - Answer-Become Wider
Imagine a sample with n = 64 and a mean of 121 that comes from a population with a
standard deviation of 16. Based on these data, what would be the 80% confidence
interval for the population mean? (Use z-scores of ±1.28 for the 80% confidence level.) -
Answer-(118.44, 123.56)
What is the point estimate for the population mean if the population standard deviation
is 10, the sample size is 100, and the sample mean is 80? - Answer-80
For which measures is it possible to compute a confidence interval? - Answer-Any
population parameter
As the standard deviation for a distribution increases, then the corresponding
confidence interval will... - Answer-Become wider
As the mean for a sample becomes greater, the width of the corresponding confidence
interval will... - Answer-Stay the same
Imagine a sample with n = 49 and a mean of 183 that comes from a population with a
standard deviation of 21. Based on these data, what would be the 99.9% confidence
interval for the population mean? (Use z-scores of ±3.29 for the 99.9% confidence
level.) - Answer-(173.13, 192.87)
Imagine a sample with n = 400 and a mean of 68 that comes from a population with a
standard deviation of 20. Based on these data, what would be the 90% confidence
interval for the population mean? (Use z-scores of ±1.64 for the 90% confidence level.) -
Answer-(66.36, 69.64)
A confidence interval specifies a range of values for a parameter estimate, whereas a(n)
_____ specifies just a single value for that parameter. - Answer-Point estimate
Which is generally more precise (in the statistical sense): a point estimate or a
confidence interval? - Answer-A point estimate
, Which is generally more accurate (in the statistical sense): a point estimate or a
confidence interval? - Answer-A confidence interval
A point estimate for the population mean is based on... - Answer-The sample mean
"Estimation" refers to a class of.... - Answer-Inferential statistics
How is the point estimate affected when the sample standard deviation increases? -
Answer-It does not change
Imagine that samples - Sample A with n = 20 and Sample B with n = 200 - are drawn
from the same population and confidence intervals are computed for the same
variables, which sample will likely have the more precise confidence interval? - Answer-
Sample B
How is a confidence interval affected when the sample standard deviation decreases? -
Answer-It becomes narrower
When the range of confidence for a confidence interval becomes lower - from 90% to
80%, for example - then the confidence interval will... - Answer-Become narrower
What is the point estimate for the population mean if the population standard deviation
is 24, the sample size is 36, and the sample mean is 110? - Answer-110
As the mean for a distribution increases, then the width of the corresponding confidence
interval will... - Answer-Stay the same
Imagine a sample with n = 49 and a mean of 60 that comes from a population with a
standard deviation of 7. Based on these data, what would be the 99.9% confidence
interval for the population mean? (Use z-score of +3.29 for the 99.9% confidence level.)
- Answer-(56.71, 63.29)
The sample mean is ________ and a confidence interval for the mean is _______. -
Answer-a descriptive statistic; an inferential statistic
Which is more precise (in the statistical sense): a point estimate or a confidence
interval? - Answer-A point estimate
If a researcher wants to test whether an experimental group is different from the general
population, the she would test... - Answer-the null hypothesis of no difference between
the group and the population.
In a two-tailed or non-directional test, if the critical value has a greater absolute value
than the observed (or test) value does, the the null hypothesis... - Answer-is not rejected
(i.e., retained).
