Only 3 Calculus question regarding population, Please help?

The answers I閳ユ獡 getting are different. Can someone please help me get the right answer? Thanks a lot

--------------------------------------...

2. The population of US was 3.9 million in 1790 and 178 million in 1960. if the rate of growth is assumed proportional to the number present, what estimate would you give for the population in 2000? (Compare your answer with the actual 2000 population, which is 275 million?)

--------------------------------------...

4. Human hair from a grave in Africa proved to have only 51% of the carbon 14 of living tissue. When was the body buried? See problem 5)

--------------------------------------...

5. (carbon Dating) all living things contain carbon 12, which is stable, and carbon 14, which is radioactive. While a plant or animals is alive, the ratio of these two isotopes of carbon remains unchanged, sinc

Only 3 Calculus question regarding population, Please help?

I can help you with question 2. You have't completed questions 4 and 5.

First get the slope of the curve of the populations, where the x-axis is people (in millions to avoid having so many numbers) and the y-axis is the year.

m= (178-3.9)/(1960-1790) = 1.0241

since the formula of a grach is (y-Y)=m(x-X) just replace the terms x and y with two points.

(y-Y)=m(x-X)

(y-178)=(1.0241)(2000-1960)

y-178=1.0241(40)

y=218.965

Since we did the y-axis in millions then the assumed population is

218 965 000 million people. Notice I'm rounding to the 6th decimal but if you want a more accurate number just recalculate all I did and write all the decimals.