Question

A variable is normally distributed with mean 23 and standard deviation 9. Use your graphing calculator to find each of the following areas. Write your answers in decimal form. Round to the nearest thousandth as needed.a) Find the area to the left of 25. b) Find the area to the left of 19. c) Find the area to the right of 23. d) Find the area to the right of 28.

Answer 1

We have a normally distributed random variable, with mean 23 and standard deviation 9.

a) We have to find the area of the left of 25.

The area to the left of 25 will be P(x<25) = 0.588.

b) We have to find the area to the left of 19:

The area to the left of 19 is P(x<19) = 0.328.

c) Find the area to the right of 23:

The area to the right of 23 is P(x>23) = 0.5.

d) Find the area to the right of 28:

The area to the right of 28 is P(x>28) = 0.289.