Answer:

Step-by-step explanation:
We require more information by I will explain in principle:
If Type A has at least 300 hours and Type B at least 400 hours.

You need to determine the Probability density function of X and Y and then subtract 1 from both

This will give you the probability of the expression.
Answer:
I would say store B.
Step-by-step explanation:
Sid earns $15 an hour.
Hope this helps! :)
Answer: 2.71
Step-by-step explanation:
We know that the formula to calculate the standard error is given by :-
, where
is the standard deviation and 'n' is the sample size.
Given : Standard deviation : 
Sample size : 
Then , the standard error of the mean is given by :-

Hence, the standard error of the mean = 2.71