Since you are given the rate of growth, the population must be computed from the integral ...

Answer:
x=19/4
Step-by-step explanation:
The product of 5 and a number x is 1/4
So because 9 and 10 are close to each other, and the fact that 10 is really easy to multiply by, you do 473 x 10 which is 4730, because you just add a 0 to the end.
This means that an estimate is 4730 or if you want to be less specific, <4730, because 9 is less than 10.
The actual product though is 4257.
Do you mean like you cant close your 4 because teachers may think its a nine? Or different ways like written, numeraly and all that?
Remark
In order to solve for the Cos(x), you need to find the missing side. You can do that by finding the Sin(x) first and then the Cos of x or you can just use the Pythagorean theorem. I'm going to do the latter.
Formula
a^2 + b^2 = c^2
Givens
a = ???
b = 32
c = 58
Sub and solve
a^2 = ???
b^2 = 1024
c^2 = 3364
a^2 + 32^2 = 58^2
1024 + a^2 = 3364 Subtract 1024 from both sides.
a^2 = 3364 - 1024
a^2 = 2340 Take the square root of both sides.
sqrt(a^2) = sqrt(2340) Break a into its prime factors.
a = sqrt(2 * 2 * 5 * 3 * 3 * 13)
Rule
For every pair of equal factors, one can be brought outside the root sign and the other is discarded.
a = 2 * 3 * sqrt(5*13)
a = 6 sqrt(65)
The cos of an angle = opposite / hypotenuse.
Cos(x) = 6*sqrt(65) / 58 <<<<< This should be the answer
If you are offered choices, you should list them
Another choice would be 6*8.0623 / 58 = 0.8340 <<<<< Answer