Question

The hours of sleep per week night among college students, is found to be Normally distributed with a mean of 6 hours and a standard deviation of 1 hour. The percentage of college students that sleep at least 8 hours per night is about Group of answer choices A) 16% B) 2.5% C) 97.5%

Answer 1

2.275%

Explanation:

Given that:

Mean, m = 6

Standard deviation, s = 1

x ≥ 8

P(x ≥ 8)

Zscore = (x - m) / s

Zscore = (8 - 6) / 1

Zscore = 2

P(Z ≥ 2) = 1 - P(Z ≤ 2)

P(Z ≤ 2) = 0.97725

P(Z ≥ 2) = 1 - 0.97725

P(Z ≥ 2) = 0.02275

0.02275 * 100%

= 2.275