Q: Suppose that X ~ N(-7,14). Find the value of x for which P(|X+7|<x)=0.44

Work so far:

-x<X + 7<x

-x-7<X<x-7

Printable View

- November 9th 2012, 10:26 PMxxlvhZ-Score Question
Q: Suppose that X ~ N(-7,14). Find the value of x for which P(|X+7|

__<__x)=0.44

Work so far:

-x__<__X + 7__<__x

-x-7__<__X__<__x-7 - November 9th 2012, 11:29 PMchiroRe: Z-Score Question
Hey xxlvh.

Remember that (X-mu)/sigma ~ N(0,1) if X is Normal(mu,sigma^2) so try getting it into P(a < Z < b) form and then using the tables to get the values for a and b [Note that the Normal distribution is symmetric around 0 for a standardized normal so P(Z < -a) = P(Z > a) for a >= 0]