Answer:
Justin’s annual percentage yield = 3.15%
Explanation:
Justin deposits $8,000 in a one-year CD at 3.1% interest, compounded daily.
WE apply compound interest formula

P is the initial amount deposited= 8000
r is the rate of interest = 3.1% = 0.031
n is the number of periods compounded = 365
t is the number of years = 1
Plug in all the values and find out A

A=8000 * (1.000084931506849315)^365
A= 8251.87
Interest amount = 8251.87 - 8000= $251.87
To find annual percentage yield we use simple interest formula
Interest = P*r*t
251.87 = 8000* r * 1
Divide by 8000 on both sides
r =0.0314838
To find out the percentage we multiply by 100
r =0.0314838 * 100 = 3.14838
Its approximately 3.15%