Question

Sketch and label, and estimate the proportion of the normal curve indicated. Then use StatCrunch. a) To the left of z 1.645 b) To the right of z 1.645 Estimate Actual

Answer 1

a) To the left of z = 1.645

The shaded region represents the area to the left of 1.645 , it is approximately 0.95

To find the actual area to the left of 1.645 using Statcruch , go to Stat menu ---> calculators --->Normal

Then plug the Mean = 0 and Std.dev = 1

Set equation P ( x ≤ 1.645 )  then click on compute.

P ( x ≤ 1.645 ) = 0.950015

So estimated area = 0.95 and actual area = 0.950015

b) To the right of z = 1.645

The shaded region represents the area to the left of 1.645 , it is approximately 0.05

To find the actual area to the left of 1.645 using Statcruch , go to Stat menu ---> calculators --->Normal

Then plug the Mean = 0 and Std.dev = 1

Set equation P ( x > 1.645 )  then click on compute.

P ( x ≤ 1.645 ) = 0.049985

So estimated area = 0.05 and actual area = 0.049985