Answer: 0.60
Step-by-step explanation:
Given: Mean : 
Standard deviation : 
The formula to calculate z is given by :-

For x= 20 minutes

The P Value =
Hence, the probability that a randomly selected shopper will spend less than 20 minutes in the store= 0.60
Answer:

Step-by-step explanation:
V=Tr^2h
V / T = r^2 h
V / Th = r^2
√V / Th

Answer:
B 16 : 24
Step-by-step explanation:
8 : 12 => when multiply by 2 = 16 : 24
I believe the answer is 420