Question

aWhen Aaron runs the 400 meter dash, his finishing times are normally distributedwith a mean of 80 seconds and a standard deviation of 2.5 seconds. Using theempirical rule, determine the interval of times that represents the middle 99.7% ofhis finishing times in the 400 meter race.

Answer 1

Answer:

The interval is [72.5, 87.5]

Step-by-step explanation:

Mean, u = 80

Standard deviation, s = 2.5

By the empirical rule, the time that represents the middle 99.7% is:

u - 3s ≤ X ≤ u + 3s

80 - 3(2.5) ≤ X ≤ 80 + 3(2.5)

80 - 7.5 ≤ X ≤ 80 + 7.5

72.5 ≤ X ≤ 87.5

The interval is [72.5, 87.5]