UCF QMB 3200 FINAL EXAM ALL LATEST
QUESTIONS AND ANSWERS SURE A+
✔✔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.
✔✔The probability that the interval estimation procedure will generate an interval that
does not contain µ is known as the - ✔✔level of significance.
✔✔As the sample size increases, the margin of error - ✔✔decreases.
✔✔When the level of confidence decreases, the margin of error - ✔✔becomes smaller.
✔✔An approximate value of a population parameter that provides limits and believed to
contain the value of the parameter is known as - ✔✔the interval estimate.
✔✔To compute the necessary sample size for an interval estimate of a population
mean, all of the following procedures are recommended when σ is unknown except -
✔✔using σ = 1.
✔✔For the interval estimation of μ when σ is known and the sample is large, the proper
distribution to use is - ✔✔the normal distribution.
✔✔What is the symbol for the sample mean? - ✔✔X bar
✔✔A student wants to determine if pennies are really fair, meaning equally likely to land
heads up or tails up. He flips a random sample of 50 pennies and finds that 28 of them
land heads up. What are the appropriate null and alternative hypotheses? - ✔✔H0:
p=.5, Ha:p not =.5.
✔✔For a lower tail test, the p-value is the probability of obtaining a value for the test
statistic - ✔✔at least as small as that provided by the sample.
✔✔The average hourly wage of computer programmers with 2 years of experience has
been $21.80. Because of high demand for computer programmers, it is believed there
has been a significant increase in the average wage of computer programmers. To test
QUESTIONS AND ANSWERS SURE A+
✔✔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.
✔✔The probability that the interval estimation procedure will generate an interval that
does not contain µ is known as the - ✔✔level of significance.
✔✔As the sample size increases, the margin of error - ✔✔decreases.
✔✔When the level of confidence decreases, the margin of error - ✔✔becomes smaller.
✔✔An approximate value of a population parameter that provides limits and believed to
contain the value of the parameter is known as - ✔✔the interval estimate.
✔✔To compute the necessary sample size for an interval estimate of a population
mean, all of the following procedures are recommended when σ is unknown except -
✔✔using σ = 1.
✔✔For the interval estimation of μ when σ is known and the sample is large, the proper
distribution to use is - ✔✔the normal distribution.
✔✔What is the symbol for the sample mean? - ✔✔X bar
✔✔A student wants to determine if pennies are really fair, meaning equally likely to land
heads up or tails up. He flips a random sample of 50 pennies and finds that 28 of them
land heads up. What are the appropriate null and alternative hypotheses? - ✔✔H0:
p=.5, Ha:p not =.5.
✔✔For a lower tail test, the p-value is the probability of obtaining a value for the test
statistic - ✔✔at least as small as that provided by the sample.
✔✔The average hourly wage of computer programmers with 2 years of experience has
been $21.80. Because of high demand for computer programmers, it is believed there
has been a significant increase in the average wage of computer programmers. To test
