The original number in a division problem is called the dividend.
Answer:

Step-by-step explanation:
Let the x-axis be the time (in years) and the y-axis the value of the fax machine (in dollars).
We know that the initial value of the fax machine is $100; in other words, when the time is zero years, the value is $100, or as an ordered pair (0, 100). We also know that after 1 year the value decreases to $80, so (1, 80).
Now we can find the slope of the line passing through those two points using the slope formula

where
is the slope
are the coordinates of the first point
are the coordinates of the second point
Replacing values:


Now, to complete our model we are using the point slope formula

where
is the slope
are the coordinates of the first point
Replacing values:




We can conclude that the correct linear depreciation model is 
You have to plug in the numbers.
So first let's plug in 13. 7*13+8=99
Now 15. 7*15+8=113
Now 18. 7*18+8=134
Lastly 20. 7*20+8=148
The answer is 13.
Divide 12 on both sides of the equation to get h by itself so it should be..15
Given:
Sample size, n = 40
Sample mean, xb = $6.88
Population std. deviation, σ = $1.92 (known)
Confidence interval = 90%
Assume normal distribution for the population.
The confidence interval is
(xb + 1.645*(σ/√n), xb - 1.645*(σ/√n)
= (6.88 + (1.645*1.92)/√40, 6.88 - (1.645*1.92)/√40)
= (7.38, 6.38)
Answer: The 90% confidence interval is (7.38, 6.38)