If Z is a standard normal random variable then the value z f

If Z is a standard normal random variable, then the value z for which P(-z < Z < z) equals 0.8764 is

Solution

P(-z < Z < z) = 0.8764

--> 2*P(0<Z<z) =0.8764

--> P(0<Z<z) =0.8764/2= 0.4382

--> P(Z<z) - P(Z<0) =0.4382

--> P(Z<z) - 0.5 =0.4382

--> P(Z<z) =0.4382+0.5 =0.9382

So z= 1.54 (from standard normal table)

Answer: B.1.54