Dawn Swift discovered that 20 years ago, the average tuition for one year at an Ivy League school was $15,000. Today, the average cost is $60,000. What is the growth rate in tuition cost over this 20minus-year period? A. 15.5%

B. 4.2%

C. 7.18%

D. 10.6%

C. 7.18%

Explanation:

Formula for calculating growth rate

= (Current amount/initial amount) ^ 1/n - 1

Given that

Initial amount = 15000

Current amount = 60000

n = 20

Therefore,

Growth rate = (60000/15000) ^1/20 - 1

= (4) ^1/20 - 1

= 1.07177 - 1

= 0.07177

To percentage we multiply by 100

So,

= 0.07177 * 100

= 7.177%

Approximately

= 7.18%