Heather received $100 for her 13th birthday if she saves it in a bank with 3% interest compounded quarterly how much money will she have in the bank by her 16th birthday

109.38

Step-by-step explanation:

Recall the formula for compound interest is as follows:

         A  =  P·(1  +  r/n)nt ,   where

    P = principal amount (initial amount deposited)

     r = annual rate of interest (in decimal form)

     t = # of years amount is deposited for

    n = # of times interest is compounded per year

    A = amount accumulated after t years, including interest

The problem asks how much money Heather will have in the bank by her 16th birthday when she deposited $100 on her 13th birthday in a bank with 3% interest compounded quarterly. From this, we have the following information:

    P = $100

    r = 0.03     ==>     3%/100% = 0.03

    t = 3 years     ==>     16 - 13 = 3

    n = 4     ==>     since there are 12 months per year and 12/4 = 3 months,

                then interest is compounded  every 3 months which is a total of 4 times per year

Therefore,

         A = P(1 + r/n)nt

            = 100(1 + 0.03/4)4·3

            = 100(1 + 0.0075)12

            = 100(1.0075)12

            = 109.38069

            ≈ 109.38

Thus, Heather will have $109.38 in the bank by her 16th birthda

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.