Intro to Stats and Analytics

Question

For a standard normal distribution, find:

P(z > 1.6)

Round your probabilty accurate to 4 decimal places.

Answer 1

Hi Lucy,

Standard normal means you have a mean (mu) of 0 and standard deviation (sigma) of 1. So, your z-score is:

z= (x-0)/1

z=x

x=1.6

That will always hold for standard normal distribution. Now, go to the z-table and look up the probability that z<1.6.

P(Z<1.6) = 0.9452

But the question asked for greater. This is where you apply the Complement Rule aka the "One Minus Trick."

P(Z>a) = 1 - P(Z<a)

P(Z>1.6) = 1 - 0.9452

P(Z>1.6) = 0.0548

I hope this helps.