Question

When a mean is 40 and standard dev. is 7.5, how do you find probability that a given value will be greater than 55.75?

Answer 1

`P_(x>55.75)=0.0179`

Explanation:

Given -

Mean `mu =40`
SD `sigma=7.5`

At `x=55.75`

`z=(x-mu)/sigma=(55.75-40)/7.5=15.75/7.5=2.1`

Probability that a given value will be greater than 55.75 = [Area between z=0 and z=`oo`] - [Area between z= 0 and z=2.1]

`P_(x>55.75)=0.5-0.4821=0.0179`
`P_(x>55.75)=0.0179`