Mean is and a standard deviation is , then the variable .
Use substitution
.
This substitution gives you that .
a. For X=130, and (the decimal value is taken from the Standard Normal Distribution Table).
b. For X=90, and for X=110, . Then (the decimal value is taken from the Standard Normal Distribution Table).
Answer:
2
Step-by-step explanation:
#a
And
#2
Attached
#3