Question

Can anyone explain the following step? \[P(Z \le -0.74) = 1 - P(Z \le 0.74)\]

Answer 1

Z is symmetric about the mean

Answer 2

but thats just an intial thought ... i read it better now :)

Answer 3

do you know the total probability under the curve?

Answer 4

The whole curve? from -ve infty to +ve infty?

Answer 5

yes, the total "area" under the normal curve

Answer 6

1?!

Answer 7

correct, the total probability (area) under the curve is 1. we also want to remember that both sides, left and right, of the mean are symmetric, or equal. 50% to the left and 50% to the right