2021
Week 8 Final Exam-
scored 128 out of 160= 80%
QUESTION 1
Of the following pairs of events, which pair has mutually exclusive events?
rolling a sum greater than 7 from two rolls of a standard die and rolling a 4 for the
first throw
drawing a 2 and drawing a 4 with replacement from a standard deck of cards
rolling a sum of 9 from two rolls of a standard die and rolling a 2 for the first roll
drawing a red card and then drawing a black card with replacement from a standard
deck of cards
QUESTION 2
Hugo averages 41 words per minute on a typing test with a standard deviation
of 7.5 words per minute. Suppose Hugo's words per minute on a typing test are
normally distributed. Let X= the number of words per minute on a typing test.
Then, X∼N(41,7.5).
Suppose Hugo types 45 words per minute in a typing test on Wednesday. The z-score
when x=45 is ________. This z-score tells you that x=45 is ________ standard
deviations to the ________ (right/left) of the mean, ________.
Correctly fill in the blanks in the statement above.
Select the correct answer below:
Suppose Hugo types 45 words per minute in a typing test on Wednesday. The z-
score when x=45 is −0.533. This z-score tells you that x=45 is 0.533 standard
deviations to the left of the mean, 41.
Suppose Hugo types 45 words per minute in a typing test on Wednesday. The z-
score when x=45 is −0.381. This z-score tells you that x=45 is 0.381 standard
deviations to the left of the mean, 41.
Suppose Hugo types 45 words per minute in a typing test on Wednesday. The z-
score when x=45 is 0.381. This z-score tells you that x=45 is 0.381 standard
deviations to the right of the mean, 41.
, Suppose Hugo types 45 words per minute in a typing test on Wednesday. The z-
score when x=45 is 0.533. This z-score tells you that x=45 is 0.533 standard
deviations to the right of the mean, 41.
QUESTION 3
A fitness center claims that the mean amount of time that a person spends at the gym
per visit is 33 minutes. Identify the null hypothesis, H0, and the alternative
hypothesis, Ha, in terms of the parameter μ.
Select the correct answer below:
H0: μ≠33; Ha: μ=33
H0: μ=33; Ha: μ≠33
H0: μ≥33; Ha: μ<33
H0: μ≤33; Ha: μ>33
QUESTION 4
A recent study suggested that 81% of senior citizens take at least one prescription
medication. Amelia is a nurse at a large hospital who would like to know whether the
percentage is the same for senior citizen patients who go to her hospital. She randomly
selects 59 senior citizens patients who were treated at the hospital and finds
that 49 of them take at least one prescription medication. What are the null and
alternative hypotheses for this hypothesis test?
{H0:p=0.81Ha:p>0.81
{H0:p≠0.81Ha:p=0.81
{H0:p=0.81Ha:p<0.81
{H0:p=0.81Ha:p≠0.81
, QUESTION 5
A doctor notes her patient's temperature in degrees Fahrenheit every hour to make sure the
patient does not get a fever. What is the level of measurement of the data.
nominal
ordinal
interval
ratio
QUESTION 6
Assume the null hypothesis, H0, is: Jacob earns enough money to afford a luxury apartment.
Find the Type I error in this scenario.
Jacob thinks he does not earn enough money to afford the luxury apartment when, in fact,
he does.
Jacob thinks he does not earn enough money to afford the luxury apartment when, in fact,
he does not.
Jacob thinks he earns enough money to afford the luxury apartment when, in fact, he does
not.
Jacob thinks he earns enough money to afford the luxury apartment when, in fact, he does.
QUESTION 7
The population standard deviation for the heights of dogs, in inches, in a city
is 3.7 inches. If we want to be 95% confident that the sample mean is
within 2 inches of the true population mean, what is the minimum sample size that can
be taken?
z0.101.282z0.051.645z0.0251.960z0.012.326z0.0052.576
Use the table above for the z-score, and be sure to round up to the nearest integer.