Ene score of the first test Is 56. Each test score is 2 points higher than the previous test score. So the score of the second test is 56+ 2 = 58.

The score of the third test is 58+ 2= 60.

And so on.

The scores form an arithmetic sequence 56, 58, 60, ......... with common difference 2.

But the values of the given exponential function \(s(n)=28*2^n\), describe a geometric sequence with common ratio 2.

So the exponential function cannot be used to model this problem.