Answer: $9 per hour at his job as a cashier and $8 per hour at his job delivering newspapers.
Step-by-step explanation:
1. Let's call the amount he got paid per hour at his job as a cashier:
.
Let's call the amount he got paid per hour at his job delivering newspapers:
.
2. Keeping on mind the information given in the problem above, you can make the following system of equations:

3. You can solve it by applying the Substitution method, as following:
- Solve for one of the variables from one of the equations and substitute it into the other equation to solve for the other variable and calculate its value.
- Substitute the value obtained into one of the original equations to solve for the other variable and calculate its value.
4. Therefore, you have:

Then:

Finally:

Therefore he got paid $9 per hour at his job as a cashier and $8 per hour at his job delivering newspapers.
Answer:
(25.53, 37.87): 95% CI
(23.59, 39.81): 99% CI
Step-by-step explanation:
The margin of error of a confidence interval is given by:

In which
is the standard deviation of the population and n is the size of the sample.
z is related to the confidence level. The higher the confidence level, the higher the values of z, and thus, we wider the confidence interval is.
In this question:
The narrower C.I. is the 95%, and the wider is the 99%. So
(25.53, 37.87): 95% CI
(23.59, 39.81): 99% CI
Question 2:
The answer is 21
The two angles are vertically opposite, which makes them equal and also means we can make an equation:
4x - 4 = 3x + 17
- 3x
x - 4 = 14
+ 4
x = 21
Question 3:
The answer is 23
Again, the angles are vertically opposite, so we can make them equal each other:
5x - 53 = 3x - 7
- 3x
2x - 53 = -7
+ 53
2x = 46
÷ 2
x = 23
I hope this helps!