# Homework Help: Simple Interest help -- investment in his savings account matured to $4,106.32 1. Oct 18, 2017 ### lil.l3b91 1. The problem statement, all variables and given/known data Michael's investment in his savings account matured to$4,106.32 at the end of 165 days. If the account was earning simple interest at a rate of 4.80% p.a., answer the following.
a. What was Michael's initial investment?

Round to the nearest cent
b. How much interest did Michael earn?

Round to the nearest cent

2. Relevant equations

p=s(1+rt) ?
I=prt
3. The attempt at a solution
s=4,106.32
t=165/365
r=0.048

s=4,106.32(1+0.048*165/365)

2. Oct 18, 2017

### Staff: Mentor

It should be divided, not multiplied.

3. Oct 19, 2017

### vela

Staff Emeritus
You've mixed up $p$ and $s$. $p$ is the final value of the investment, and $s$ is the amount initially invested. Make sure you understand what each variable in a formula represents instead of plugging numbers in willy-nilly.