UCF QMB 3200 Final Exam Questions with
Complete Solutions
Which of these best describes a sampling distribution of a statistic? It is the distribution of
all of the statistics calculated from all possible samples of the same sample size.
The probability distribution of all possible values of the sample proportion is the sampling
distribution of p.
For a fixed confidence level and population standard deviation, if we would like to cut our
margin of error in half, we should take a sample size that is four times as large as the
original sample size.
We can reduce the margin of error in an interval estimate of p by doing any of the following
except increasing the planning value p* to .5.
When computing the sample size needed to estimate a proportion within a given margin of error
for a specific confidence level, what planning value of p should be used when no estimate of p is
available? 0.50
,A statistics teacher started class one day by drawing the names of 10 students out of a hat and
asked them to do as many pushups as they could. The 10 randomly selected students averaged 15
pushups per person with a standard deviation of 9 pushups. Suppose the distribution of the
population of number of pushups that can be done is approximately normal. Which of the
following statements is true? A t distribution should be used because σ is unknown.
The z value for a 99% confidence interval estimation is 2.58
In an interval estimation for a proportion of a population, the critical value of z at 99%
confidence is 2.576.
In interval estimation, as the sample size becomes larger, the interval estimate becomes
narrower.In general, higher confidence levels provide larger confidence intervals.
One way to have high confidence and a small margin of error is to increase the sample
size.
From a population that is normally distributed, a sample of 30 elements is selected and the
standard deviation of the sample is computed. For the interval estimation of μ, the proper
distribution to use is the t distribution with 29 degrees of freedom.
,As the number of degrees of freedom for a t distribution increases, the difference between the t
distribution and the standard normal distribution becomes smaller.
The value added and subtracted from a point estimate in order to develop an interval estimate of
the population parameter is known as the margin of error.
What is the symbol for the population mean? If the population follows a normal distribution, the
confidence interval is _____ and can be used for any sample size. If the population does not
follow a normal distribution, the confidence interval will be _____. Which of the following
choices correctly complete this statement? exact; approximate.
The t value for a 99% confidence interval estimation based upon a sample of size 10 is
3.250.
To compute the necessary sample size for an interval estimate of a population proportion, all of
the following procedures are recommended when p is unknown except using .95 as an
estimate.
, Using an α = .04, a confidence interval for a population proportion is determined to be .65 to .75.
If the level of significance is decreased, the interval for the population proportion
becomes wider.
For a fixed confidence level and population standard deviation, if we would like to cut our
margin of error to 1/3 of the original size, we should take a sample size that is nine times
as large as the original sample size.
The sampling distribution of can be approximated by a normal distribution as long as np>
5 and n(1-p)>5 greater or equals.
When "s" is used to estimate "σ," the margin of error is computed by using the t
distribution.
The margin of error in an interval estimate of the population mean is a function of all of the
following except the sample mean.
For a fixed sample size, n, in order to have a higher degree of confidence, the margin of error and
the width of the interval must be larger.
Complete Solutions
Which of these best describes a sampling distribution of a statistic? It is the distribution of
all of the statistics calculated from all possible samples of the same sample size.
The probability distribution of all possible values of the sample proportion is the sampling
distribution of p.
For a fixed confidence level and population standard deviation, if we would like to cut our
margin of error in half, we should take a sample size that is four times as large as the
original sample size.
We can reduce the margin of error in an interval estimate of p by doing any of the following
except increasing the planning value p* to .5.
When computing the sample size needed to estimate a proportion within a given margin of error
for a specific confidence level, what planning value of p should be used when no estimate of p is
available? 0.50
,A statistics teacher started class one day by drawing the names of 10 students out of a hat and
asked them to do as many pushups as they could. The 10 randomly selected students averaged 15
pushups per person with a standard deviation of 9 pushups. Suppose the distribution of the
population of number of pushups that can be done is approximately normal. Which of the
following statements is true? A t distribution should be used because σ is unknown.
The z value for a 99% confidence interval estimation is 2.58
In an interval estimation for a proportion of a population, the critical value of z at 99%
confidence is 2.576.
In interval estimation, as the sample size becomes larger, the interval estimate becomes
narrower.In general, higher confidence levels provide larger confidence intervals.
One way to have high confidence and a small margin of error is to increase the sample
size.
From a population that is normally distributed, a sample of 30 elements is selected and the
standard deviation of the sample is computed. For the interval estimation of μ, the proper
distribution to use is the t distribution with 29 degrees of freedom.
,As the number of degrees of freedom for a t distribution increases, the difference between the t
distribution and the standard normal distribution becomes smaller.
The value added and subtracted from a point estimate in order to develop an interval estimate of
the population parameter is known as the margin of error.
What is the symbol for the population mean? If the population follows a normal distribution, the
confidence interval is _____ and can be used for any sample size. If the population does not
follow a normal distribution, the confidence interval will be _____. Which of the following
choices correctly complete this statement? exact; approximate.
The t value for a 99% confidence interval estimation based upon a sample of size 10 is
3.250.
To compute the necessary sample size for an interval estimate of a population proportion, all of
the following procedures are recommended when p is unknown except using .95 as an
estimate.
, Using an α = .04, a confidence interval for a population proportion is determined to be .65 to .75.
If the level of significance is decreased, the interval for the population proportion
becomes wider.
For a fixed confidence level and population standard deviation, if we would like to cut our
margin of error to 1/3 of the original size, we should take a sample size that is nine times
as large as the original sample size.
The sampling distribution of can be approximated by a normal distribution as long as np>
5 and n(1-p)>5 greater or equals.
When "s" is used to estimate "σ," the margin of error is computed by using the t
distribution.
The margin of error in an interval estimate of the population mean is a function of all of the
following except the sample mean.
For a fixed sample size, n, in order to have a higher degree of confidence, the margin of error and
the width of the interval must be larger.
