UCF QMB 3200 FINAL EXAM QUESTIONS & ANSWERS
Doubling the size of the sample will - Answers - reduce the standard error of the mean
The sample mean is the point estimator of - 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 - Answers - the same probability of being selected
Which of the following statements regarding the sampling distribution of sample means
is incorrect? - 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 - 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
- Answers - central limit theorem.
Cluster sampling is - Answers - a probability sampling method.
The central limit theorem states that - 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 -
Answers - sample statistic
The sampling distribution of is the - Answers - probability distribution of all possible
values of the sample proportion.
Which of the following is not a symbol for a parameter? - Answers - S.
The sample statistic characteristic s is the point estimator of - 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 - Answers - sampling distribution.
Which of the following is a point estimator? - Answers - S.
As a rule of thumb, the sampling distribution of the sample proportion can be
approximated by a normal probability distribution when - 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 - Answers - normal because of the central limit theorem.
We can reduce the margin of error in an interval estimate of p by doing any of the
following except - 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? - 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? - Answers - A t
distribution should be used because σ is unknown.
The z value for a 99% confidence interval estimation is - Answers - 2.58
In an interval estimation for a proportion of a population, the critical value of z at 99%
confidence is - Answers - 2.576.
In interval estimation, as the sample size becomes larger, the interval estimate -
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 - 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 - Answers - 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 - Answers - 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 - Answers - 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? - Answers - exact;
approximate.
, The t value for a 99% confidence interval estimation based upon a sample of size 10 is -
Answers - 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
- Answers - 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 - Answers - 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 -
Answers - nine times as large as the original sample size.
The central limit theorem is important in Statistics because it enables reasonably
accurate probabilities to be determined for events involving the sample average -
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 - Answers - The sample
Which of these best describes a sampling distribution of a statistic? - 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 -
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 - Answers - four times
as large as the original sample size.
The sampling distribution of can be approximated by a normal distribution as long as -
Answers - 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 -
Answers - t distribution.
The margin of error in an interval estimate of the population mean is a function of all of
the following except the - Answers - 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 - Answers - must be larger.
Doubling the size of the sample will - Answers - reduce the standard error of the mean
The sample mean is the point estimator of - 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 - Answers - the same probability of being selected
Which of the following statements regarding the sampling distribution of sample means
is incorrect? - 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 - 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
- Answers - central limit theorem.
Cluster sampling is - Answers - a probability sampling method.
The central limit theorem states that - 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 -
Answers - sample statistic
The sampling distribution of is the - Answers - probability distribution of all possible
values of the sample proportion.
Which of the following is not a symbol for a parameter? - Answers - S.
The sample statistic characteristic s is the point estimator of - 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 - Answers - sampling distribution.
Which of the following is a point estimator? - Answers - S.
As a rule of thumb, the sampling distribution of the sample proportion can be
approximated by a normal probability distribution when - 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 - Answers - normal because of the central limit theorem.
We can reduce the margin of error in an interval estimate of p by doing any of the
following except - 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? - 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? - Answers - A t
distribution should be used because σ is unknown.
The z value for a 99% confidence interval estimation is - Answers - 2.58
In an interval estimation for a proportion of a population, the critical value of z at 99%
confidence is - Answers - 2.576.
In interval estimation, as the sample size becomes larger, the interval estimate -
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 - 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 - Answers - 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 - Answers - 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 - Answers - 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? - Answers - exact;
approximate.
, The t value for a 99% confidence interval estimation based upon a sample of size 10 is -
Answers - 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
- Answers - 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 - Answers - 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 -
Answers - nine times as large as the original sample size.
The central limit theorem is important in Statistics because it enables reasonably
accurate probabilities to be determined for events involving the sample average -
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 - Answers - The sample
Which of these best describes a sampling distribution of a statistic? - 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 -
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 - Answers - four times
as large as the original sample size.
The sampling distribution of can be approximated by a normal distribution as long as -
Answers - 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 -
Answers - t distribution.
The margin of error in an interval estimate of the population mean is a function of all of
the following except the - Answers - 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 - Answers - must be larger.