Bstat exam 2 questions well answered to
pass
Find the z value such that P(Z ≤ z) = 0.9082. - correct answer ✔✔z = 1.33
If the p-value for a hypothesis test is 0.07 and the chosen level of significance is α = 0.05, then
the correct conclusion is to ____________________. - correct answer ✔✔not reject the null
hypothesis
A random sample of size 100 is taken from a population described by the proportion p = 0.60.
The probability that the sample proportion is less than 0.55 is ______. - correct answer
✔✔0.1537
If the underlying populations cannot be assumed to be normal, then by the central limit
theorem, the sampling distribution of x1- x2 is approximately normal only if the sum of the
sample observations is sufficiently large—that is, when n1 + n2 >= 30 - correct answer ✔✔False
Do men really spend more money on St. Patrick's Day as compared to women? A recent survey
found that men spend an average of $43.87 while women spend an average of $29.54. Assume
that these data were based on a sample of 100 men and 100 women and the population
standard deviations of spending for men and women are $32 and $25, respectively. Using 1%
confidence level, which of the following is the correct conclusion for this test? - correct answer
✔✔Reject H0: µ1 − µ2 ≤ 0 and therefore conclude that on average men spend more money
than women on St. Patrick's Day.
The Department of Education would like to test the hypothesis that the average debt load of
graduating students with a bachelor's degree is equal to $17,000. A random sample of 34
students had an average debt load of $18,200. It is believed that the population standard
deviation for student debt load is $4,200. The α is set to 0.05. The p-value for this hypothesis
test would be ______. - correct answer ✔✔0.0957
, A basketball coach wants to know how many free throws an NBA player shoots during the
course of an average practice. The coach takes a random sample of 43 players and finds the
average number of free throws shot per practice was 225 with a standard deviation of 35.
Construct a 99% confidence interval for the average number of free throws in practice. - correct
answer ✔✔[210.5992, 239.4008]
A 99% confidence interval for the population mean yields the following results: [−3.79, 5.86]. At
the 1% significance level, what decision should be made regarding the following hypothesis test
with Ho:μ = 0,HA:μ ≠ 0? - correct answer ✔✔Do not reject Ho; we cannot conclude that the
mean differs from zero.
A ________ is a numerical quantity not computed from the data of a sample and is the size of
the critical region used in reaching a decision on whether or not to reject the null hypothesis. -
correct answer ✔✔significance level
The owner of a large car dealership believes that the financial crisis decreased the number of
customers visiting her dealership. The dealership has historically had 800 customers per day.
The owner takes a sample of 100 days and finds the average number of customers visiting the
dealership per day was 750. Assume that the population standard deviation is 350. At the 5%
significance level, the decision is to ___________. - correct answer ✔✔do not reject Ho; we
cannot conclude that the mean number of customers visiting the dealership is significantly less
than 800
A 99% confidence interval estimate can be interpreted to mean that - correct answer ✔✔if all
possible samples of the same size are taken and confidence interval estimates are developed,
99% of them would include the true population mean somewhere within their interval.
What is the minimum sample size required to estimate a population mean with 95% confidence
when the desired margin of error or bound on error is B = 1.5? The population standard
deviation is known to be 10.75. - correct answer ✔✔n = 198
pass
Find the z value such that P(Z ≤ z) = 0.9082. - correct answer ✔✔z = 1.33
If the p-value for a hypothesis test is 0.07 and the chosen level of significance is α = 0.05, then
the correct conclusion is to ____________________. - correct answer ✔✔not reject the null
hypothesis
A random sample of size 100 is taken from a population described by the proportion p = 0.60.
The probability that the sample proportion is less than 0.55 is ______. - correct answer
✔✔0.1537
If the underlying populations cannot be assumed to be normal, then by the central limit
theorem, the sampling distribution of x1- x2 is approximately normal only if the sum of the
sample observations is sufficiently large—that is, when n1 + n2 >= 30 - correct answer ✔✔False
Do men really spend more money on St. Patrick's Day as compared to women? A recent survey
found that men spend an average of $43.87 while women spend an average of $29.54. Assume
that these data were based on a sample of 100 men and 100 women and the population
standard deviations of spending for men and women are $32 and $25, respectively. Using 1%
confidence level, which of the following is the correct conclusion for this test? - correct answer
✔✔Reject H0: µ1 − µ2 ≤ 0 and therefore conclude that on average men spend more money
than women on St. Patrick's Day.
The Department of Education would like to test the hypothesis that the average debt load of
graduating students with a bachelor's degree is equal to $17,000. A random sample of 34
students had an average debt load of $18,200. It is believed that the population standard
deviation for student debt load is $4,200. The α is set to 0.05. The p-value for this hypothesis
test would be ______. - correct answer ✔✔0.0957
, A basketball coach wants to know how many free throws an NBA player shoots during the
course of an average practice. The coach takes a random sample of 43 players and finds the
average number of free throws shot per practice was 225 with a standard deviation of 35.
Construct a 99% confidence interval for the average number of free throws in practice. - correct
answer ✔✔[210.5992, 239.4008]
A 99% confidence interval for the population mean yields the following results: [−3.79, 5.86]. At
the 1% significance level, what decision should be made regarding the following hypothesis test
with Ho:μ = 0,HA:μ ≠ 0? - correct answer ✔✔Do not reject Ho; we cannot conclude that the
mean differs from zero.
A ________ is a numerical quantity not computed from the data of a sample and is the size of
the critical region used in reaching a decision on whether or not to reject the null hypothesis. -
correct answer ✔✔significance level
The owner of a large car dealership believes that the financial crisis decreased the number of
customers visiting her dealership. The dealership has historically had 800 customers per day.
The owner takes a sample of 100 days and finds the average number of customers visiting the
dealership per day was 750. Assume that the population standard deviation is 350. At the 5%
significance level, the decision is to ___________. - correct answer ✔✔do not reject Ho; we
cannot conclude that the mean number of customers visiting the dealership is significantly less
than 800
A 99% confidence interval estimate can be interpreted to mean that - correct answer ✔✔if all
possible samples of the same size are taken and confidence interval estimates are developed,
99% of them would include the true population mean somewhere within their interval.
What is the minimum sample size required to estimate a population mean with 95% confidence
when the desired margin of error or bound on error is B = 1.5? The population standard
deviation is known to be 10.75. - correct answer ✔✔n = 198
