Question

1. On the below problems, you should do 4 things: A) Draw a picture and shade the area you are asked to find, B) Draw an equivalent picture that represents the situation on the standard normal curve (carefully label places on the horizontal axis for A and B!), C) Find the area using the Z-table in your book (no work to show here), and D) write two lines of R code − one that finds the area on the original picture (part A), and one that finds the area on the standard normal curve (part B). These lines of code should give the same answer, and they should match part C.

a. Curve: X = N(µ = −1, σ = 3), Area to find: P(X > 0).

b. Y = N(µ = 0, σ = 1.2), P(|Y | > 2.4)

Answer 1

a. Curve: X = N(µ = −1, σ = 3), Area to find: P(X > 0).

 1-pnorm(0,-1,3)
[1] 0.3694413

b. Y = N(µ = 0, σ = 1.2), P(|Y | > 2.4)

1- (pnorm(2.4,0,1.2) - pnorm(-2.4,0,1.2))
[1] 0.04550026