Answer:

Step-by-step explanation:
First, let's change those variables to x and y, just for the sake of convenience. In order to find the inverse of a function algebraically, switch the x and y coordinates, then solve for the new y. Letting y = A(n) and x = n (we will switch them back when we're done):
y = 3x - 20. This is linear; a line with a slope of 3 and a y-intercept of -20. When we switch the x and the y, we get:
x = 3y - 20. Now we solve for the new y. Begin by adding 20 to both sides:
x + 20 = 3y. Now divide both sides by 3:
, or to write it in slope-intercept form, like the function you started with:

This is also a line, with a slope of 1/3 and a y-intercept of +20/3
Now, replacing:

That is how to write the inverse using function notation. The little -1 as an exponent tells us that this is the inverse of the function A(n).
Brian (I think you meant Brian haha..) is incorrect because the tenth place is the number right after the decimal which is a 4. If you are rounding to the tenth place that means that you have to look at the number to the right of that, which is 4. 5 and up means you round up and 4 and down means you round down. This is a 4, so you keep the 4 after the decimal and get rid of the last 4. Therefore, when rounded it would be: 4.4.
Hope this helped! Good luck! :)
Answer:
The size of the sample is 23 scientists.