Question

If $700 is invested in an account that pays 3% compounded annually, the total amount, A(t), in the account after t years is Ant 700(1.03)^t.

Required:
a. Find the average rate of change per year of the total amount in the account for the first four years of the investment (from t= 0 to t= 4).
b. Find the average rate of change per year of the total amount in the account for the second four years of the investment (from t=4 to t=8)
c. Estimate the instantaneous rate of change for t =4.
d. The average rate of change per year of the total amount in the account for the first years of the investment â(from t= 0 to t=4â) is ___________â$
e. The average rate of change per year of the total amount in the account for the second years of the investment â(from t= 0 to t=4â) is_____________ â$
f. The instantaneous rate of change for t=4 is about â$_____________

Answer 1

21.96 ; 24.72

Explanation:

Given that :

Give the equation:

A(t) = 700(1.03)^t

A.)

Average rate of change over the first 4 years ;

(t=0 to t=4)

At t = 0

A(0) = 700(1.03)^0 = 700

A(1) = 700(1.03)^1 = 721

A(2) = 700(1.03)^2 = 742.63

A(3) = 700(1.03)^3 = 764. 9089

A(4) = 700(1.03)^4 = 787.856167

[(721 - 700) + (742.63 - 721) + (764.9089 - 742.63) + (787.856167 - 764.9089)] / 4

= 87.856167 / 4

= 21.96404175

= 21.96

Over the 2nd 4 years :

A(4) = 700(1.03)^4 = 787.856167

A(5) = 700(1.03)^5 = 811.49185201

A(6) = 700(1.03)^6 = 835.8366075703

A(7) = 700(1.03)^7 = 860.911705797409

A(8) = 700(1.03)^8 = 886.73905697133127

[(811.49185201 - 787.856167) + (835.8366075703 - 811.49185201) + (860.911705797409 - 835.8366075703) + (886.73905697133127 - 860.911705797409)] / 4

= 98.88288997133127 / 4

= 24.72