Answer:
The z-score for an income of $2,100 is 1.
Step-by-step explanation:
If X
N (µ, σ²), then
, is a standard normal variate with mean, E (Z) = 0 and Var (Z) = 1. That is, Z
N (0, 1).
The distribution of these z-variate is known as the standard normal distribution.
Given:
µ = $2,000
σ = $100
<em>x</em> = $2,100
Compute the <em>z</em>-score for the raw score <em>x</em> = 2100 as follows:

Thus, the z-score for an income of $2,100 is 1.
Answer: Sally walked 3 minutes faster per mile
Hope it helped!
8: 20
9: 90
I am so sorry if this is wrong. I am not good at this type of things