The ages of ten seniors are 71, 68, 75, 68, 62, 80, 73, 68, 67, 70. The 90^th percentile is

Question

Quizplus · Accepted Answer

To find the 90th percentile, we need to arrange the data in numerical order: 62, 67, 68, 68, 68, 70, 71, 73, 75, 80 The formula for finding the percentile is: n = (P/100) x N where n is the number of values at the percentile, P is the percentile desired (90 in this case), and N is the total number of values in the data set (10 in this case). Plugging in the values, we get: n = (90/100) x 10 = 9 So the 90th percentile is the ninth value in the ordered list, which is 75. To find the 91st percentile, we need to use the same formula with P = 91: n = (91/100) x 10 = 9.1 Since we can't have a fractional value for n, we use the next highest integer value, which is 10. So the 91st percentile is the tenth value in the ordered list, which is 80. Therefore, the 90^th percentile is between 75 and 80. The average of these two values is (75+80)/2 = 77.5. Hence, the best choice is D, with an explanation as above.

The Ages of Ten Seniors Are 71, 68, 75, 68