MATH 225N Week 8 Statistics Final Exam 2021

Week 8 Final Examscored
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 zscore
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 zscore
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 zscore
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.