Question

Last year 715 students went to the local high school. This year 823 students went to the school. Which equation can be used to find the

percent of increase, p, since last year?

Answer 1

Explanation:

college level question ? for a simple function definition and understanding % ?

since 823 is an increase based on 715, we know

100% = 715

1% = 100%/100 = 715/100 = 7.15

823 = 100% + x = 715 + x

108 = x

how many % are these 108 ?

as many % as 1% fits into 108 :

108/7.15 = 15.1048951...%

now, let's bring all these steps into one equation :

p = (823 - 715)/(715/100) = 100(823 - 715)/715 =

= 100(823/715 - 1)

FYI

and if we use this as a function based on the number of new students (x) this year :

p(x) = 100(x/715 - 1)