The reaction time (in seconds) to a stop at a red light for a group of adult men was found to be
0.74, 0.71, 0.41, 0.82, 0.74, 0.85, 0.99, 0.71, 0.57, 0.85, 0.57, 0.55

-What is the 90^th percentile?

Question

Quizplus · Accepted Answer

To find the 90th percentile, first, arrange the data in ascending order: 0.41, 0.55, 0.57, 0.57, 0.71, 0.71, 0.74, 0.74, 0.82, 0.85, 0.85, 0.99. For the 90th percentile of 12 data points, calculate the position using the formula: P = (90/100) * N = 0.9 * 12 = 10.8. Since this is not a whole number, round up to the nearest whole number, which is 11. The value in the 11th position is 0.85, making it the 90th percentile.

The Reaction Time (In Seconds) to a Stop at a Red