Question

The weekly salaries of teachers in one state are normally distributed with a mean of $490 and a standard deviation of $45. What is the probability that a randomly selected teacher earns more than $460 a week?

Answer 1

0.74751

Explanation:

Using the z score formula

z = (x-μ)/σ, where

x is the raw score = $460

μ is the population mean = $490

σ is the population standard deviation = $45

z = 460 - 490/45

z = -0.66667

Probability value from Z-Table:

P(x < 460) = 0.25249

P(x > 460) = 1 - P(x<460)

P(x > 460) = 1 - 0.25249

P(x > 460) = 0.74751

The probability that a randomly selected teacher earns more than $460 a week is 0.74751