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