Fatima opened a savings account with $7,500. She decided to deposit that same amount semiannually. This account earns 3.975% interest compounded semiannually. Exercises 5-7 are about Fatima's account. 5. What is the future value of the account after 10 years?​

A = $11117.25

Step-by-step explanation:

Given the following data;

Principal = $7,500

Interest rate = 3.975% = 3.975/100 = 0.03975

Number of times, n = 2

Time, t = 10 years

To find the future value, we would use the compound interest formula;

Where;

A is the future value.

P is the principal or starting amount.

r is annual interest rate.

n is the number of times the interest is compounded in a year.

t is the number of years for the compound interest.

Substituting into the equation, we have;

A = $11117.25

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4