Question 7 12 points) Use the graph showing Maria's account balance to answer the question that follows.
Account balance ($)
600
550
500
450
400
350
300
(5,270.27)
250
(10, 306.54)
(0, 234)
200
150
100
50
Time (years)
+
2 3 4 5 6 7 8 9 10 11 12 13 14 15
What is the interest rate on Maria's account? (2 points)
a
3.1%
b
7.3%
13.8%
Ос
Od
15.5%