Question

In 1990, the average monthly bill for cellular telephone service was $80.90. From 1990-1997, the monthly bill decreased by 8.6% per year (in other words, each year the bill is 91.4% of
what is was the previous year (Source: Statistical Abstract of the United States).
Part a: Write a formula for the average monthly cellular telephone bill in terms of the year. Let n = 1 represent 1990.
Part b: What was the average monthly bill in 1993

Answer 1

A)The formula for the average monthly cellular telephone bill in terms of the year will be A = 80.90(0.914)ⁿ⁻¹

B)The average monthly bill in 1993 willl be $ 61.77

What is the percentage?

The quantity of anything is stated as though it were a fraction of a hundred. A fraction of 100 can be used to express the ratio.

The formula for the average monthly cellular telephone bill in terms of the year willl be,

A=P(R/100)ⁿ

A = 80.90(0.914)ⁿ⁻¹

The average monthly bill in 1993 is found as ;

n=4 for 1993

A=P(R/100)ⁿ

A = 80.90(0.914)³⁻¹

A=$ 61.77

Hence the formula for the average monthly cellular telephone bill in terms of the year will be A = 80.90(0.914)ⁿ⁻¹ and the average monthly bill in 1993 willl be $ 61.77.

To learn more about percentages, refer to:

brainly.com/question/13450942

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