QNT 2020 MIDTERM REVIEW QUESTIONS WITH
VERIFIED ANSWERS
(TRUE OR FALSE) The Empirical Rule can be applied to any distribution, unlike
Chebyshev's theorem. - Answers - FALSE
(TRUE OR FALSE) A 90 percent confidence interval will be wider than a 95 percent
confidence interval, ceteris paribus. - Answers - FALSE
(TRUE OR FALSE) Outliers are data values that fall beyond ±2 standard deviations
from the mean. - Answers - FALSE
(TRUE OR FALSE) A frequency distribution usually has equal bin widths. - Answers -
TRUE
(TRUE OR FALSE) A scatter plot requires two quantitative variables (i.e., not
categorical data). - Answers - TRUE
(TRUE OR FALSE) A sample of size 5 shows a mean of 45.2 and a sample standard
deviation of 6.4. The standard error of the sample mean is approximately 2.86. -
Answers - TRUE b/c the standard error is the standard deviation divided by the square
root of the sample size. We would use Student's t instead of z to construct a confidence
interval for the population mean, but this problem did not ask for a confidence interval.
(TRUE OR FALSE) The efficiency of an estimator depends on the variance of the
estimator's sampling distribution. - Answers - TRUE b/c efficiency is measured by the
variance of the estimator's sampling distribution.
(TRUE OR FALSE) For a sample size of 20, a 95 percent confidence interval using the t
distribution would be wider than one constructed using the z distribution. - Answers -
TRUE b/c student's t is always larger than z for the same level of confidence.
(TRUE OR FALSE) When the sample standard deviation is used to construct a
confidence interval for the mean, we would use the Student's t distribution instead of the
normal distribution. - Answers - TRUE b/c we should use the t distribution when the
population variance is unknown.
(TRUE OR FALSE) The level of significance refers to the probability of making a Type II
error. - Answers - FALSE b/c the level of significance is the desired probability of Type I
error.
VERIFIED ANSWERS
(TRUE OR FALSE) The Empirical Rule can be applied to any distribution, unlike
Chebyshev's theorem. - Answers - FALSE
(TRUE OR FALSE) A 90 percent confidence interval will be wider than a 95 percent
confidence interval, ceteris paribus. - Answers - FALSE
(TRUE OR FALSE) Outliers are data values that fall beyond ±2 standard deviations
from the mean. - Answers - FALSE
(TRUE OR FALSE) A frequency distribution usually has equal bin widths. - Answers -
TRUE
(TRUE OR FALSE) A scatter plot requires two quantitative variables (i.e., not
categorical data). - Answers - TRUE
(TRUE OR FALSE) A sample of size 5 shows a mean of 45.2 and a sample standard
deviation of 6.4. The standard error of the sample mean is approximately 2.86. -
Answers - TRUE b/c the standard error is the standard deviation divided by the square
root of the sample size. We would use Student's t instead of z to construct a confidence
interval for the population mean, but this problem did not ask for a confidence interval.
(TRUE OR FALSE) The efficiency of an estimator depends on the variance of the
estimator's sampling distribution. - Answers - TRUE b/c efficiency is measured by the
variance of the estimator's sampling distribution.
(TRUE OR FALSE) For a sample size of 20, a 95 percent confidence interval using the t
distribution would be wider than one constructed using the z distribution. - Answers -
TRUE b/c student's t is always larger than z for the same level of confidence.
(TRUE OR FALSE) When the sample standard deviation is used to construct a
confidence interval for the mean, we would use the Student's t distribution instead of the
normal distribution. - Answers - TRUE b/c we should use the t distribution when the
population variance is unknown.
(TRUE OR FALSE) The level of significance refers to the probability of making a Type II
error. - Answers - FALSE b/c the level of significance is the desired probability of Type I
error.
