SOLUTION: Suppose Z is a standard normal random variable. If P(-z < Z < z) = 0.5588, find z. Find P( -2.28 < Z < -0.63). Please help me out! Thank you so much

Algebra ->  Probability-and-statistics -> SOLUTION: Suppose Z is a standard normal random variable. If P(-z < Z < z) = 0.5588, find z. Find P( -2.28 < Z < -0.63). Please help me out! Thank you so much      Log On


   

Question 992907: Suppose Z is a standard normal random variable.
If P(-z < Z < z) = 0.5588, find z.
Find P( -2.28 < Z < -0.63).
Please help me out!
Thank you so much
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Suppose Z is a standard normal random variable.
If P(-z < Z < z) = 0.5588, find z.
Since 1/2 the probability is to the right of the mean
find the z-value with a left-tail = 0.5+(1/2)(0.5588) = 0.7795
Ans: z = invNorm(0.7795) = 0.77051
---------
Find P(-2.28 < Z < -0.63) = normalcdf(-2.28,-0.63) = 0.2530
---------
Cheers,
Stan H.
-----------