Question

Assume that x has a normal distribution with the specified mean and standard deviation. Find the indicated probability. (Round your answer to four decimal places.)

μ = 40; σ = 16
P(50 ≤ x ≤ 70) =______.

Answer 1

0.2356

Explanation:

Given that:

μ = 40; σ = 16

P(50 ≤ x ≤ 70) :

Using the Zscore formula :

(x - μ) / σ

P((50 - 40) / 16 ≤ Z ≤ (70 - 40) / 16)

P(50 ≤ x ≤ 70) = P(0.625 ≤ Z ≤ 1.875)

Using the Z probability calculator :

P(Z ≤ 1.875) - P(Z ≤ 0.625) -

0.9696 - 0.73401

= 0.23559

= 0.2356