Simple Statistics
The numbers of sodas purchased each day from a machine over nine consecutive days are below.
2 25 26 34 28 28 22 31 17
What is the median?
(a) 19.5 (b) 28 (c) 26 (d) 23.6 (e) 9.5
(c) 26
The following are age and assessed value data for the house Jack built in 1980:
Age (x) in years 5 10 15 20 25 30
Value (y) in $ 125,000 152,000 177,000 210,000 275,000 255,000
The equation of the regression line is
(a) y = 0 .00015 −12.92x
(b) y = 0 .00015x −12.92
(c) y = −6011.43x + 93800
(d) y = 6011.43 + 93800x
(e) y = 6011.43x + 93800
(e) y = 6011.43x + 93800
Let A represent the event that the sum of the two faces showing is exactly 7. What is P(A)?
(a) 7/36 (b) 6/36 (c) 10/36 (d) 7/6
(b) 6/36
APSU wants a 95% confidence interval for the average length of cafeteria cockroaches. The margin
of error is to be no more than 0.1 cm in width, and they believe the standard deviation of the lengths
to be about 0.5 cm. What is the minimum required number of cockroaches they must measure?
(a) 9 (b) 10 (c) 20 (d) 96 (e) 97
(e) 97
The number of cars sold in a week is
(a) quantitative continuous (b) quantitative discrete (c) categorical
(b) quantitative discrete
The numbers of sodas purchased each day from a machine over nine consecutive days are below.
2 25 26 34 28 28 22 31 17
What is the mean?
(a) 19.5 (b) 28 (c) 26 (d) 23.6 (e) 9.5
(d) 23.6
The following are age and price data for six Corvettes:
Age in years (x) 1 2 2 4 5 10
Price in $ (y) 49,000 46,500 44,900 36,000 39,000 28,500
The equation of the regression line is
(a) y = 49524x + 2219x
(b) y = 49524 + 2219x
(c) y = −49524 −2219x
(d) y = 49524x −2219
(e) y = 49524 −2219x
(e) y = 49524 −2219x
Let B represent the event that the left die shows a 2. What is P (A|B)?
(a) 1/2 (b) 1 (c) 5/6 (d) 1/6 (e) 2/6
(d) 1/6
Increasing the confidence level
(a) increases the sample mean.
(b) increases the margin of error.
(c) decreases the margin of error.
(d) decreases the width of the confidence interval.
(e) decreases the sample mean.
(b) increases the margin of error.
The mean and standard deviation of a standard normal random variable are
(a) μ = 1, σ = 1
(b) μ = 0, σ = 0
(c) μ = 0, σ = 1
(d) μ = 1/2, σ = 1/2
(e) μ = 1, σ = 0
(c) μ = 0, σ = 1
The numbers of sodas purchased each day from a machine over nine consecutive days are below.
2 25 26 34 28 28 22 31 17
What is the sample standard deviation?
(a) 19.5 (b) 28 (c) 26 (d) 23.6 (e) 9.5
(e) 9.5
The following are age and price data for six Corvettes:
Age in years (x) 1 2 2 4 5 10
Price in $ (y) 49,000 46,500 44,900 36,000 39,000 28,500
Use the regression line equation to predict the price of a 4.5 year-old Corvette.
(a) $39538.50 (b) $220639 (c) -$59509.50 (d) $59509.50 (e) $225077
(a) $39538.50
Given the left die shows a 5, what is the probability that the sum of the two faces is greater
than or equal to 9?
(a) 3/10 (b) 2/6 (c) 3/6 (d) 10/36 (e) 4/10
(c) 3/6
The p-value is
(a) the probability of accepting the null hypothesis.
(b) the probability of failing to reject the null hypothesis when the null hypothesis is true.
(c) the probability of observing a test statistic value as extreme as the one calculated from the sample.
(d) the probability of failing to reject the null hypothesis when the null hypothesis is false.
(e) the probability of rejecting the null hypothesis when the null hypothesis is false.
(c) the probability of observing a test statistic value as extreme as the one calculated from the sample.
If P(A) = 0.4, P(B) = 0.5, and P(A ∩ B) = 0.2, calculate P(AC)
(a) 1 (b) 0.8 (c) 0.7 (d) 0.6 (e) 0.5
(d) 0.6
The numbers of sodas purchased each day from a machine over nine consecutive days are below.
2 25 26 34 28 28 22 31 17
What is the third quartile?
(a) 10 (b) 29.5 (c) 26 (d) 23.6 (e) 32
(b) 29.5
True/False? Jack’s test score was at the 20th percentile and Jill’s was at the 70th percentile. This means about
50% of the scores fell between Jill’s and Jane’s scores.
True
Given that the left die shows a 4, 5, or 6, what is the probability that the sum is 5?
(a) 1/18 (b) 1/36 (c) 4/36 (d) 5/36 (e) 1/2
Type I error occurs when
(a) we fail to reject H0 in favor of Ha when H0 is true.
(b) we fail to reject H0 in favor of Ha when Ha is true.
(c) we reject H0 in favor of Ha when H0 is true.
(d) we reject H0 in favor of Ha when Ha is true.
(e) we reject H0 and Ha in favor of the test statistic.
(c) we reject H0 in favor of Ha when H0 is true.
Let X denotes the number of ”heads” observed in five tosses of a coin. This experiment can be modeled as
(a) a normal experiment with mean 1/2 and standard deviation 5.
(b) a normal experiment with mean 5 and standard deviation 1/2.
(c) a binomial experiment with mean 5 and standard deviation 1/2.
(d) a binomial experiment with 2 trials and success probability 1/5.
(e) a binomial experiment with 5 trials and success probability 1/2.
(e) a binomial experiment with 5 trials and success probability 1/2.
The numbers of sodas purchased each day from a machine over nine consecutive days are below.
2 25 26 34 28 28 22 31 17
If you had to choose exactly one data value to be an outlier, which would it be?
Use the 1.5 × IQR rule.
(a) 2 (b) 34 (c) 17 (d) 28 (e) 95
(a) 2
True/False? Data with an r value of -0.97 are strongly correlated.
True
A represents the event that the sum of the two faces showing is greater than or equal to 9 and that B represents the event that the left die shows a 5. Are events A and B independent?
(a) No because P(A|B) =/ P(A).
(b) No because P(A|B) =/ P(B).
(c) No because P(A) =/ P(B).
(d) Yes because P(A) =/ P(B).
(e) Yes because P(A|B) =/ P(B).
(a) No because P(A|B) =/ P(A).
In a simple random sample of 1000 APSU students, 750 of them commute to campus.
A 95% confidence interval for the actual proportion who commute is
(a) [0.72, 0.78]
(b) [0.74, 0.76]
(c) [0.67, 0.83]
(d) [0.70, 0.80]
(e) [0.745, 0.755]
(a) [0.72, 0.78]
Christmas tree heights have a bell-shaped distribution with mean 65 inches and standard deviation 9
inches. A farmer samples 1000 trees.
One tree had a z-score of 3.25. Which is correct?
(a) This tree height is 3.25 standard deviation below the mean
(b) This tree height is 3.25 inches above the mean
(c) This tree height can be considered as an outlier from the other tree heights
(d) This tree height is about average
(e) None of the above
(c) This tree height can be considered as an outlier from the other tree heights