Answer: 0.7
Locate the tenths place which is just to the right of the decimal point. We see a 6 in this spot. Just to the right of this 6 is the value 8. Since 8 is larger than 5, we bump the 6 up to 7 and erase everything else to the right. You can think of it like this
0.687 ---> 0.6 which bumps up to 0.7
This is like saying 687 is closer to 700 than it is to 600
Answer:
$68.44 for each additional belt
Step-by-step explanation:
The cost and revenue functions are:

The profit function, P(x), is given by subtracting the cost function from the revenue function.

The derivate of the profit function gives us the rate at which profit changes:

For x = 484, the rate of change is:

Profit is increasing by $68.44 for each additional belt
I think this is the answer X = 3 + 1/2y