Step-by-step explanation:
Difference per month = 28
=> January = February - 28 = 66-28 = 38
The wrong step is step 4, because you only need one conversion.
The formula to convers pounds to kilograms is

Obviously, the inverse formula is

So, you're given an input of 142 pounds. To convert it in kilograms, plug that value into out formula:

and this is the answer you're looking for, so you need no more steps.
Answer:
-2.20 < z < 2.20
Step-by-step explanation:
You are saying the entire area = 0.9722
so 1 - 0.9722 = 0.0278
then we want it to fit in the middle of the normal curve with center 0
so...
0.0278/2 =0.0139 this corresponds to 2.20 on the z-score chart