QMB3200 Ch. 8 HW Exam Questions And
Answers
A random sample of 30 business students required an average of
103.4 minutes to complete a QMB 3200 exam. Assume that the
population standard deviation to complete the exam was 15.7
minutes. The margin of error for a 98% confidence interval around
this sample mean is ________. -
correct answer ✅6.67
A random sample of 150 mortgages in the state of Florida was
randomly selected. From this sample, 17 were found to be
delinquent on their current payment. The 98% confidence interval
for the proportion based on this sample is ________. -
correct answer ✅(0.053, 0.174)
A random sample of 13 hotels in Tallahassee had an average nightly
room rate of $172.10 with a sample standard deviation of $23.90.
The approximate standard error of the mean for this sample is
________. -
correct answer ✅6.63
Verizon Wireless would like to estimate the proportion of
households that use cell phones for their phone service without a
land line. A random sample of 150 households was selected and 48
relied strictly on cell phones for their service. The margin of error
, QMB3200 Ch. 8 HW Exam Questions And
Answers
for a 90% confidence interval for the proportion based on this
sample is ________. -
correct answer ✅0.0627
Increasing the sample size when calculating a confidence interval
while keeping the confidence level constant will -
correct answer ✅reduce the margin of error resulting in a
narrower (more precise) confidence interval.
The definition of a 90% confidence interval is that we expect that
close to 90% of a large number of sample means drawn from a
population will produce confidence intervals that include that
population's mean. -
correct answer ✅True
A local church has a total population consisting of 480 adult
members. The church's administrators would like to estimate the
average weekly donation per member per week. A random sample
of 65 members was found to have an average donation of $50.40.
Further, the population standard deviation is $12.30. The 95%
confidence interval to estimate the average weekly donation is
________. Hint: don't forget the finite population correction factor.
Answers
A random sample of 30 business students required an average of
103.4 minutes to complete a QMB 3200 exam. Assume that the
population standard deviation to complete the exam was 15.7
minutes. The margin of error for a 98% confidence interval around
this sample mean is ________. -
correct answer ✅6.67
A random sample of 150 mortgages in the state of Florida was
randomly selected. From this sample, 17 were found to be
delinquent on their current payment. The 98% confidence interval
for the proportion based on this sample is ________. -
correct answer ✅(0.053, 0.174)
A random sample of 13 hotels in Tallahassee had an average nightly
room rate of $172.10 with a sample standard deviation of $23.90.
The approximate standard error of the mean for this sample is
________. -
correct answer ✅6.63
Verizon Wireless would like to estimate the proportion of
households that use cell phones for their phone service without a
land line. A random sample of 150 households was selected and 48
relied strictly on cell phones for their service. The margin of error
, QMB3200 Ch. 8 HW Exam Questions And
Answers
for a 90% confidence interval for the proportion based on this
sample is ________. -
correct answer ✅0.0627
Increasing the sample size when calculating a confidence interval
while keeping the confidence level constant will -
correct answer ✅reduce the margin of error resulting in a
narrower (more precise) confidence interval.
The definition of a 90% confidence interval is that we expect that
close to 90% of a large number of sample means drawn from a
population will produce confidence intervals that include that
population's mean. -
correct answer ✅True
A local church has a total population consisting of 480 adult
members. The church's administrators would like to estimate the
average weekly donation per member per week. A random sample
of 65 members was found to have an average donation of $50.40.
Further, the population standard deviation is $12.30. The 95%
confidence interval to estimate the average weekly donation is
________. Hint: don't forget the finite population correction factor.
