Answer:

33 gallons of water to begin with.
Step-by-step explanation:
So we essentially are given two coordinates: (6,87) and (21,222). To find an equation, we simply need to find the slope and y-intercept. We know it's a linear equation because it's a steady stream, meaning a constant slope.
The slope is:

So, the rate at which the stream flows is 9 gallons per minute.
Now, let's find the initial amount of water. To do this, we can use point-slope form. Pick either of the two points. I'm going to use (6,87).

So, there were 33 gallons of water in the tank to begin with.
I’m so sorry but I don’t have a clue! But you’ll get it eventually
Answer:
- $52
- this estimate is a little low
Explanation:
a) I might choose 6 1/2 hours and $8 per hour, so the estimated earnings would be ...
6(8) +(1/2)(8) = 52 dollars . . . . estimated earnings
These values are purposely chosen so that one is a little high and the other is a little low, hopefully producing a closer estimate than if both numbers were high (as 7 hours, $8, for example).
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b) Using 800 instead of 790 means the pay estimate is about 1/80 = 1.25% high.
Using 6 1/2 instead of 6 3/4 means the hours estimate is about 1/27 ≈ 3.7% low.
So, we expect the product of these values to be slightly low, perhaps by about 2.5%.
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<em>Comment on estimating</em>
If you can estimate the error in the estimate with some reasonable accuracy, you can use that to adjust the estimate to a pretty close value.