Compare the idea, physical, and computer models.

The idea model is used to for relationships between variables, such as time and distance, that can be graphed or be placed into an equation. A physical model, on the other hand, is generally used for objects, such as a cell, to show the various parts and their orientation in respect to each other. A computer model is used to track weather patterns and other factors to predict natural events.

Explanation:

9.9 years

a = p(1 + rt) . . account balance after time t at rate r starting with principal p

3000 = 2500(1 + 0.0202t) . . filling in the given numbers

1.2 = 1 + 0.0202t . . divide by 2500

0.2 = 0.0202t . . . subtract 1

0.2/0.0202 = t ≈ 9.901

it will take about 9.9 years for the account balance to reach $3000.