# An online streaming video site has increased its user base 10% during the last 4 months. The site now has 490,804 active users. How many users did the site have 4 months ago?

Apr 27, 2017

$= 446185$

#### Explanation:

$\frac{490804}{1.1}$

$= 446185$

Apr 27, 2017

$\frac{490804}{1.4641} = 335225$

#### Explanation:

base = initial base*(1 + rate of increase)^4
initial base = 490804/(1+0.1)^4 = 490804/(1.1)^4

Using Pascal triangle
(1 + .1)^4 = (1 + 4*1(0.1) + 6*1*(0.1)^2 + 4*1(0.1)^3 + (0.1)^4

${\left(1 + .1\right)}^{4} = 1.4641$

so that initial base = $\frac{490804}{1.4641} = 335225$