Question

What formula to use for determining the probability that the mean stress level for a sample of 70 employees will fall above 52? (mean =50; STD 10)

Answer 1

0.4207

Explanation:

Determine z-score

`z=\frac{\bar{x}-\mu}{\sigma/√(n)}\\ \\z=(52-50)/(10/√(70))\\ \\z\approx1.6733`

Find P(Z>1.6733)

`P(Z > 1.6733)=normalcdf(1.6733,\infty)\approx0.4207`

Therefore, the probability that the mean stress level for a sample of 70 employees will fall above 52 is 0.4207