ALgebra 2 rate of change

Question

At the beginning of each week, Isaac recorded the amount of money he had in his checking account. The information is provided in the table below.

Week Money

1 $17.25

2 $23.26

3 $25.92

4 $38.79

5 $59.57

6 $82.37

What is the average rate of change in the amount of money in the checking account from Week 1 to Week 5?

(a) $10.58 per week

(b) $9.61 per week

(c) $7.84 per week

(d) $6.01 per week

Answer 1

There are two methods for solving this, both of which arrive at the same answer. You can either:

1. Subtract each week's total from the previous week's total from week 5 to week 1, getting 4 distinct "differences". Then, you can add those numbers and divide by four to get the average change.
2. You can skip the individual subtractions by week and just subtract the week 1 amount from the week 5 amount before dividing by the total number of weeks (4) that have passed. Since the question is asking for rate of change, it's asking for "change in amount per week". Thus, you can use this method by figuring out the total amount of change in dollar amount then divide by the total number of weeks.

Give it a shot; both should arrive at the same answer!