When serenity runs the 400 meter dash, her finishing times are normally distributed with a mean of 90 seconds and a standard deviation of 2.5 seconds. using the empirical rule, determine the interval of times that represents the middle 95% of her finishing times in the 400 meter race.

[85, 95] seconds

Step-by-step explanation:

The empirical rule says 95% of the distribution is within 2 standard deviations of the mean. Two standard deviations is 2·(2.5 s) = 5 s, so 95% of her times are in the range 90 ±5 s. As an interval, that is [85, 95] seconds.

[85, 95] seconds

Step-by-step explanation:The empirical rule says 95% of the distribution is within 2 standard deviations of the mean. Two standard deviations is 2·(2.5 s) = 5 s, so 95% of her times are in the range 90 ±5 s. As an interval, that is [85, 95] seconds.

29 is the correct answer

step-by-step explanation:

step-by-step explanation:

ok so im not 100% sure but you would start by adding 5.1t and 1.9t beacuse they have the same variable. that is 7t.   then add -3.6 + 1.2 which is -2.4

so then keep that as -2.4 + 7t. i apologize if this is incorrect. best luck on your test < 3