Question

In 1982, the number of Starbucks was 5 shops. It has exponentially grown by 21% yearly. Let t= the number of years since 1982. Find an equation for this growth and find the number of Starbucks predicted in 2015

Answer 1

Answer:

The number of Starbucks predicted in 2015 is 2697.

Step-by-step explanation:

There is an increment of 21% on yearly basis.

In 1982, the number of starbucks were 5.

In 1983, the number of starbucks will be $5\times \frac{121}{100}$.

In 1984, The number will become $5\times\frac{121}{100} \times\frac{121}{100} = 5\times (\frac{121}{100} )^{2}$.

In the year of X, the number of starbucks will be $5\times(\frac{121}{100} )^{t}$, where t = X - 1982.

In 2015, t = 2015 - 1982 = 33.

The number of starbucks in 2015 is $5\times(\frac{121}{100} )^{33} = 2697$.