Exercise 17 Page 173

If we have a savings account, the bank pays us interest for the use of our money. To calculate the interest I, we use the simple interest formula. I= p r t, where... I& =Interest p& = Principal r& = Annual interest rate t& = Time (in years)We are given that the principal is $3000, the interest rate is 5.5 %, and the time is 9 months. We want to find the simple interest earned to the nearest cent. Keep in mind that 9 months represent 912 of a year and that 5.5 % is written in decimal form as 0.055. p= 3000, r= 0.055, t= 9/12 To calculate the interest, let's substitute these values into the simple interest formula and evaluate the right-hand side.

I=prt

SubstituteValues

Substitute values

I= 3000( 0.055)( 9/12)

Multiply

Multiply

I=165(9/12)

NumToDivByOne

a=a/1

I=165/1(9/12)

MultFrac

Multiply fractions

I=165* 9/1* 12

Multiply

Multiply

I=1485/12

CalcQuot

Calculate quotient

I=123.75

The simple interest earned is $ 123.75.