Find the z value to the right of the mean so that:. a. 54.78% of the area under the distribution curve lies to the left of it.
b. 69.85% of the area under the distribution curve lies to the left of it.
c. 88.10% of the area under the distribution curve lies to the left of it.

a) z = 0.12

b) z = 0.52

c) z = 1.18

Step-by-step explanation:

The  z values is the area under the curve lying to its left

a) Hence, P (Z<z) = 0.5478

Taking the value of z from the standard normal table, we get -

z = 0.12

b) P (Z<z) = 0.6985

Taking the value of z from the standard normal table, we get -

z = 0.52

c) P (Z<z) = 0.8810

Taking the value of z from the standard normal table, we get -

z = 1.18

both equations and proportions are better.

1) 2/5

2) zero=0/1

3) zero=0/2

4) -4/5

5) undefined=3/0