Answer:
4676.85 cell phone subscribers were in Glenwood in 1990 .
Step-by-step explanation:
As the exponential increase function is denoted by.
[tex]y = a (1 + r)^{t}[/tex]
Where a is the initial value , r is the rate of interest in the decimal form and t is time.
As given
In 1985, there were 285 cell phone subscribers in the small town of Glenwood.
The number of subscribers increased by 75% per year after 1985.
75% is written in the decimal form
[tex]= \frac{75}{100}[/tex]
= 0.75
a = 285
r = 0.75
As the year changes from 1985 to 1990 .
t = 1990 - 1985
t = 5
Put in the expontential increase function.
[tex]y = 285 (1 + 0.75)^{5}[/tex]
[tex]y = 285 (1.75)^{5}[/tex]
y = 285 × 16.41
y = 4676.85
Therefore 4676.85 cell phone subscribers were in Glenwood in 1990 .
