ok lets see if i can explain this properly. sorry it's long but i had to explain it properly
A) to calculate the final value received at the end of a period of time when the percentage is known we divide the percentage by 100 to give it to us as a decimal ( lets call this "X". this value is then added to 1 to give 1+X.
1+X is then put to the power of the period of time passed. in this case 3. so this gives us 1+X to the power of 3.
the initial value is then multiplied by 1+X to the power of three to give the value of the final answer.
so the equation used is final value = initial value * (1+X)^3
to give us the percentage we rearrange the equation to give us.
x= (cube root of, final value/initial value) -1
= (cube root of, 42830/42000) -1
=0.0065 to two sig figs
as mentioned before to find X we divide the interest rate by 100. so to find the interest rate here we must multiply X by 100
=0.65%
B) 6%/ 100 = 0.06
0.06+1=1.06
1.06^4=1.263 to 3 decimal places
1.263*42000=53046
yes pablo will have 50000 at the end of the 4 years
