Question

Suppose that X is normally distributed with a mean of 8 and a standard deviation of 2. Determine P left parenthesis 3 less than X less than 7 right parenthesis . Round your answer to two decimal places.

Answer 1

Solution :

P(3 < x < 7)

= P[(3 - 8)/ 2) < (x - ) /  < (7 - 8) / 2) ]

= P(-2.5 < z < -0.5)

= P(z < -0.5) - P(z < -2.5)

= .3023

Answer = 0.30