Answer:
I hope this will help!
Step-by-step explanation:
This is the concept of probability and statistics, the z-score associated by the probability of 25% will be obtained using the z-tables, and hence we shall have:
P(x)=25=0.25
thus checking the z-score that gives us the probability of 0.25 we get:
-0.67
the answer is z=-0.67
It is
-25+21/2= -25/0 + 21/2 = -3/8