The ratio of the sales in 1998 was given as:
\[
\text{Peach} : \text{Lemon} : \text{Litchi} = 2.1 : 1.5 : 1.0
\]
The sale of Litchi increased by 10% in 2004. Hence, the increase in Litchi’s sale is:
\[
10% \text{ increase in Litchi} = \frac{3 \times 110}{100} = 3.3%
\]
The total sale of drinks will still follow the same ratio. We now calculate the total sale by considering the increase in Litchi’s sale. To account for this, we find the total by using the formula:
\[
10% = 3.3
\]
Now,
\[
1% = \frac{3.3}{10}
\]
Then, the total sale is:
\[
\text{Total Sale} = \frac{3.3}{10} \times 4.6 = 15.18 \text{ million (approx.)}
\]
Thus, the approximate total sale of the three drinks in 2004 is 15 million.