For each problem, select the best response.
(a) The scores of adults on an IQ test is approximately Normal with mean 100 and standard deviation 15. Corinne scores 118 on such test. Her z-score is about
A. 7.87
B. 1.2
C. 18
D. 0.67
E. None of the above.
(b) To completely specify the shape of a Normal distribution, you must give
A. the median and the standard deviation.
B. the mean and the median.
C. the five-number summary.
D. the mean and the standard deviation.
E. All of the above.
(c) Which of these variables is least likely to have a Normal distribution?
A. Heights of 100 white pine trees in a forest.
B. Income per person for 150 different countries.
C. Lengths of 50 newly hatched pythons.
D. None of the above.