UCF QMB 3200 Final Exam UPDATED
QUESTIONS AND CORRECT ANSWERS
Doubling the size of the sample will - CORRECT ANSWER reduce the standard error
of the mean
The sample mean is the point estimator of - CORRECT ANSWER U
A simple random sample of size n from an infinite population of size N is to be selected.
Each possible sample should have - CORRECT ANSWER the same probability of
being selected
Which of the following statements regarding the sampling distribution of sample means is
incorrect? - CORRECT ANSWER 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 -
CORRECT ANSWER 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 - CORRECT
ANSWER central limit theorem.
Cluster sampling is - CORRECT ANSWER a probability sampling method.
The central limit theorem states that - CORRECT ANSWER 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 - CORRECT
ANSWER sample statistic
,The sampling distribution of is the - CORRECT ANSWER probability distribution of
all possible values of the sample proportion.
Which of the following is not a symbol for a parameter? - CORRECT ANSWER S.
The sample statistic characteristic s is the point estimator of - CORRECT ANSWER σ..
The distribution of values taken by a statistic in all possible samples of the same size from the
same population is called a - CORRECT ANSWER sampling distribution.
Which of the following is a point estimator? - CORRECT ANSWER S.
As a rule of thumb, the sampling distribution of the sample proportion can be approximated
by a normal probability distribution when - CORRECT ANSWER n(1 - p) ≥ 5 and np ≥
5.
A sample of 92 observations is taken from an infinite population. The sampling distribution
of is approximately - CORRECT ANSWER 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 - CORRECT
ANSWER 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 - CORRECT ANSWER The sample
Which of these best describes a sampling distribution of a statistic? - CORRECT
ANSWER 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 -
CORRECT ANSWER 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 - CORRECT
ANSWER 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 - CORRECT ANSWER 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? - CORRECT ANSWER 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? - CORRECT ANSWER At
distribution should be used because σ is unknown.
The z value for a 99% confidence interval estimation is - CORRECT ANSWER 2.58
In an interval estimation for a proportion of a population, the critical value of z at 99%
confidence is - CORRECT ANSWER 2.576.
In interval estimation, as the sample size becomes larger, the interval estimate - CORRECT
ANSWER 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 - CORRECT
ANSWER increase the sample size.
QUESTIONS AND CORRECT ANSWERS
Doubling the size of the sample will - CORRECT ANSWER reduce the standard error
of the mean
The sample mean is the point estimator of - CORRECT ANSWER U
A simple random sample of size n from an infinite population of size N is to be selected.
Each possible sample should have - CORRECT ANSWER the same probability of
being selected
Which of the following statements regarding the sampling distribution of sample means is
incorrect? - CORRECT ANSWER 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 -
CORRECT ANSWER 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 - CORRECT
ANSWER central limit theorem.
Cluster sampling is - CORRECT ANSWER a probability sampling method.
The central limit theorem states that - CORRECT ANSWER 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 - CORRECT
ANSWER sample statistic
,The sampling distribution of is the - CORRECT ANSWER probability distribution of
all possible values of the sample proportion.
Which of the following is not a symbol for a parameter? - CORRECT ANSWER S.
The sample statistic characteristic s is the point estimator of - CORRECT ANSWER σ..
The distribution of values taken by a statistic in all possible samples of the same size from the
same population is called a - CORRECT ANSWER sampling distribution.
Which of the following is a point estimator? - CORRECT ANSWER S.
As a rule of thumb, the sampling distribution of the sample proportion can be approximated
by a normal probability distribution when - CORRECT ANSWER n(1 - p) ≥ 5 and np ≥
5.
A sample of 92 observations is taken from an infinite population. The sampling distribution
of is approximately - CORRECT ANSWER 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 - CORRECT
ANSWER 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 - CORRECT ANSWER The sample
Which of these best describes a sampling distribution of a statistic? - CORRECT
ANSWER 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 -
CORRECT ANSWER 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 - CORRECT
ANSWER 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 - CORRECT ANSWER 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? - CORRECT ANSWER 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? - CORRECT ANSWER At
distribution should be used because σ is unknown.
The z value for a 99% confidence interval estimation is - CORRECT ANSWER 2.58
In an interval estimation for a proportion of a population, the critical value of z at 99%
confidence is - CORRECT ANSWER 2.576.
In interval estimation, as the sample size becomes larger, the interval estimate - CORRECT
ANSWER 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 - CORRECT
ANSWER increase the sample size.
