Diana invested $3000 in a savings account for 3 years. She earned $450 in interest over that time period. What interest rate did she earn? Use the formula I=Prt to find your answer, where I is interest, P is principal, r is rate and t is time. Enter your solution in decimal form rounded to the nearest hundredth. For example, if your solution is 12%, you would enter 0.12.

Question

anonymous · Answer

3000*X*3=450
9000*X=450
X=$$\frac{ 450 }{ 9000 }$$
X=.05
Her interest rate for 3 years was 5%.

tkhunny · Answer

What is "X"?

I = Prt

We are given:

"Diana invested $3000 in a savings account"

P = $3000

"for 3 years."

t = 3

"She earned $450 in interest over that time period."

I = $450

Thus: $450 = $3000 * r * 3

Solve for r.

anonymous · Answer

thanks guys

anonymous · Answer

X is suppose to be r, my fault for the confusion.

anonymous · Answer

thats  0.05 in a decimal ?

anonymous · Answer

yes. .05 as a percent is 5%. But as a decimal is 0.05