# Need help understanding questions

• May 8th 2008, 05:24 AM
Jasona
Need help understanding questions
I need help understanding these questions:

It asks to derive the mathematical models, using my calculator I achieve these answers by plotting points, sketching the graph and find the LinearReg (y=ax+b)

a = 28.6857142
b = -20.387600493
r = 0.87600493
r2 = 0.76738464

So y = 28.6857142x + -20.387600493

The exponential graph (y = aebx)

a = 4.73037226
b = 0.69703135
r = 0399017859
r2 = 0.98045364

The question then asks - (By considering the value of r2 comment on the suitability).

What I said is that the closer r2 is to 1 the more suitable it is. The exponential is very suitable, whereas the Linear function is less suitable than the exponential function but still suitable.

When it asks derive the following, does it want me to derive the answers or just figure it out using the calculator – but then asks us to comment on the suitability (Are my results correct)?

Here are the tables:

TABLE 1
Number of seasons \ Population Number
0 4
1 12
2 22
3 30
4 74
5 166

TABLE 2
Number of seasons \ Population Number
0 134
1 61
2 24
3 10
4 5
5 2
6 0
• May 8th 2008, 11:52 AM
masters
Try this for a better understanding of \$\displaystyle r \$ and \$\displaystyle r^2\$.

Statistics 2 - Correlation Coefficient and Coefficient of Determination

That first plot looks more quadratic than linear.