The model for the sales is
and the candle company's sales in 2000 is $324.63
Finding a model for the sales
From the question, we have the following parameters that can be used in our computation:

Integrate the function
So, we have


We have that
The sales in 1999 is $256.7 million
So, we have

1333.6 + c = 256.7
So, we have
c = 256.7 - 1333.6
c = -1076.89
So, we have

In 2000, we have t = 10
So:

S = 324.63
Hence, the sales is 324.63