181k views
3 votes
A person invests 9000 dollars in a bank. The bank pays 4.75% interest compounded quarterly. To the nearest tenth of a year, how long must the person leave the money in the bank until it reaches 12600 dollars?

User Asthomas
by
3.4k points

2 Answers

2 votes
the answer is 7.1 because the answer is 7.1
User Andykenward
by
3.6k points
2 votes

7.1 years

Explanation:

Principle P = 9000 dollars

Rate r = 4.75% = 0.0475

Total Amount A = 12600 dollars

compounded quarterly n = 4

Time t = ?

t = ln(A/P) / n[ln(1 + r/n)]

t = ln(12,600/9,000) / ( 4 × [ln(1 + 0.011875/4)] )

t = 7.1 years

so the answer is 7.1 years

User Yulian
by
2.9k points