Answer:
-12
Step-by-step explanation:
We start with the equation: 
Substitute the variables: 
Solve using order of operations (start with multiplication): 
And then addition/subtration: 
Answer:
y = -10x + 6
Step-by-step explanation:
The answer is $12 an hour because 12 times 3 is 36 and half of 12 is 6 so add 6 to 36 and you get 42.
Part a)
The simple random sample of size n=36 is obtained from a population with

and

The sampling distribution of the sample means has a mean that is equal to mean of the population the sample has been drawn from.
Therefore the sampling distribution has a mean of

The standard error of the means becomes the standard deviation of the sampling distribution.

Part b) We want to find

We need to convert to z-score.

Part c)
We want to find

We convert to z-score and use the normal distribution table to find the corresponding area.

Part d)
We want to find :

We convert to z-scores and again use the standard normal distribution table.

Answer:
The simplification is done below.
Step-by-step explanation:

= 
=
= 