Question

Automobile sales in a country were 20.6 million thisâ year, a 4.9â% increase over last year. Find the number of auto sales in the country last year.?
number â(Round to the nearestâ tenth.)?

Answer 1

Answer: 19.6 million

Step-by-step explanation:

The exponential growth function is given by :-

$A=A_0(1+r)^x$, where A is the initial amount , r is rate of interest and x is time period.

Given : The automobile sales in a country this year : A= 20.6 million

The rate of increase : r = 4.9 %=0.049

For last year , we take x = 1 , then the required exponential equation will be :-

$20.6=A_0(1+0.049)^1\\\\\Rightarrow\ A_0=\dfrac{20.6}{1.049}=19.63775\approx19.6$

Hence, the  number of auto sales in the country last year = 19.6 million.