UCF QMB 3200 Final Exam with correct
solutions
Doubling the size of the sample will - ** VERIFIED ANSWERS **✔✔reduce the standard error of
the mean
The sample mean is the point estimator of - ** VERIFIED ANSWERS **✔✔U
A simple random sample of size n from an infinite population of size N is to be selected. Each
possible sample should have - ** VERIFIED ANSWERS **✔✔the same probability of being selected
Which of the following statements regarding the sampling distribution of sample means is incorrect?
- ** VERIFIED ANSWERS **✔✔The standard deviation of the sampling distribution is the standard
deviation of the population.
A simple random sample of size n from an infinite population is a sample selected such that - **
VERIFIED ANSWERS **✔✔each element is selected independently and is selected from the same
population
The fact that the sampling distribution of sample means can be approximated by a normal
probability distribution whenever the sample size becomes large is based on the - ** VERIFIED
ANSWERS **✔✔central limit theorem.
Cluster sampling is - ** VERIFIED ANSWERS **✔✔a probability sampling method.
The central limit theorem states that - ** VERIFIED ANSWERS **✔✔if the sample size n is large,
then the sampling distribution of the sample mean can be approximated by a normal distribution.
The value of the _____ is used to estimate the value of the population parameter - ** VERIFIED
ANSWERS **✔✔sample statistic
,The sampling distribution of is the - ** VERIFIED ANSWERS **✔✔probability distribution of all
possible values of the sample proportion.
Which of the following is not a symbol for a parameter? - ** VERIFIED ANSWERS **✔✔S.
The sample statistic characteristic s is the point estimator of - ** VERIFIED ANSWERS **✔✔σ..
The distribution of values taken by a statistic in all possible samples of the same size from the same
population is called a - ** VERIFIED ANSWERS **✔✔sampling distribution.
Which of the following is a point estimator? - ** VERIFIED ANSWERS **✔✔S.
As a rule of thumb, the sampling distribution of the sample proportion can be approximated by a
normal probability distribution when - ** VERIFIED ANSWERS **✔✔n(1 - p) ≥ 5 and np ≥ 5.
A sample of 92 observations is taken from an infinite population. The sampling distribution of is
approximately - ** VERIFIED ANSWERS **✔✔normal because of the central limit theorem.
The central limit theorem is important in Statistics because it enables reasonably accurate
probabilities to be determined for events involving the sample average - ** VERIFIED ANSWERS
**✔✔when the sample size is large regardless of the distribution of the variable.
The distribution of values taken by a statistic in all possible samples of the same size from the same
population is the sampling distribution of - ** VERIFIED ANSWERS **✔✔The sample
Which of these best describes a sampling distribution of a statistic? - ** VERIFIED ANSWERS
**✔✔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 - ** VERIFIED
ANSWERS **✔✔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 - ** VERIFIED ANSWERS **✔✔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 -
** VERIFIED ANSWERS **✔✔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? - ** VERIFIED ANSWERS **✔✔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? - ** VERIFIED ANSWERS **✔✔A t distribution should be used because σ is unknown.
The z value for a 99% confidence interval estimation is - ** VERIFIED ANSWERS **✔✔2.58
In an interval estimation for a proportion of a population, the critical value of z at 99% confidence is -
** VERIFIED ANSWERS **✔✔2.576.
In interval estimation, as the sample size becomes larger, the interval estimate - ** VERIFIED
ANSWERS **✔✔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 - ** VERIFIED ANSWERS
**✔✔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 - ** VERIFIED ANSWERS **✔✔t distribution with 29 degrees of freedom.
solutions
Doubling the size of the sample will - ** VERIFIED ANSWERS **✔✔reduce the standard error of
the mean
The sample mean is the point estimator of - ** VERIFIED ANSWERS **✔✔U
A simple random sample of size n from an infinite population of size N is to be selected. Each
possible sample should have - ** VERIFIED ANSWERS **✔✔the same probability of being selected
Which of the following statements regarding the sampling distribution of sample means is incorrect?
- ** VERIFIED ANSWERS **✔✔The standard deviation of the sampling distribution is the standard
deviation of the population.
A simple random sample of size n from an infinite population is a sample selected such that - **
VERIFIED ANSWERS **✔✔each element is selected independently and is selected from the same
population
The fact that the sampling distribution of sample means can be approximated by a normal
probability distribution whenever the sample size becomes large is based on the - ** VERIFIED
ANSWERS **✔✔central limit theorem.
Cluster sampling is - ** VERIFIED ANSWERS **✔✔a probability sampling method.
The central limit theorem states that - ** VERIFIED ANSWERS **✔✔if the sample size n is large,
then the sampling distribution of the sample mean can be approximated by a normal distribution.
The value of the _____ is used to estimate the value of the population parameter - ** VERIFIED
ANSWERS **✔✔sample statistic
,The sampling distribution of is the - ** VERIFIED ANSWERS **✔✔probability distribution of all
possible values of the sample proportion.
Which of the following is not a symbol for a parameter? - ** VERIFIED ANSWERS **✔✔S.
The sample statistic characteristic s is the point estimator of - ** VERIFIED ANSWERS **✔✔σ..
The distribution of values taken by a statistic in all possible samples of the same size from the same
population is called a - ** VERIFIED ANSWERS **✔✔sampling distribution.
Which of the following is a point estimator? - ** VERIFIED ANSWERS **✔✔S.
As a rule of thumb, the sampling distribution of the sample proportion can be approximated by a
normal probability distribution when - ** VERIFIED ANSWERS **✔✔n(1 - p) ≥ 5 and np ≥ 5.
A sample of 92 observations is taken from an infinite population. The sampling distribution of is
approximately - ** VERIFIED ANSWERS **✔✔normal because of the central limit theorem.
The central limit theorem is important in Statistics because it enables reasonably accurate
probabilities to be determined for events involving the sample average - ** VERIFIED ANSWERS
**✔✔when the sample size is large regardless of the distribution of the variable.
The distribution of values taken by a statistic in all possible samples of the same size from the same
population is the sampling distribution of - ** VERIFIED ANSWERS **✔✔The sample
Which of these best describes a sampling distribution of a statistic? - ** VERIFIED ANSWERS
**✔✔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 - ** VERIFIED
ANSWERS **✔✔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 - ** VERIFIED ANSWERS **✔✔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 -
** VERIFIED ANSWERS **✔✔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? - ** VERIFIED ANSWERS **✔✔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? - ** VERIFIED ANSWERS **✔✔A t distribution should be used because σ is unknown.
The z value for a 99% confidence interval estimation is - ** VERIFIED ANSWERS **✔✔2.58
In an interval estimation for a proportion of a population, the critical value of z at 99% confidence is -
** VERIFIED ANSWERS **✔✔2.576.
In interval estimation, as the sample size becomes larger, the interval estimate - ** VERIFIED
ANSWERS **✔✔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 - ** VERIFIED ANSWERS
**✔✔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 - ** VERIFIED ANSWERS **✔✔t distribution with 29 degrees of freedom.
