Indexed Totals RPI associated question

can somebody pse tell me how you work out the indexed total, when you are given the annual sales figure, the index factor and the RPI
For instance, if the annual sales figure is 1476, the index factor is 195.5/173.4 , how do you get the indexed total to be 1664 ?
For instance, if the annual sales figure is 1476, the index factor is 195.5/173.4 , how do you get the indexed total to be 1664 ?
Comments
Past sales Value
Past index value
Current index value
Then divide Past sales by Past index value and multiply by present index value
Therefore £1476 divide by 173.4 times 195.5 equal £1664 equivalent value of sales in today’s term
In practice we use it to compare performance year on year. Generally the gross profit doesn't have a radical change - if it does it can mean there is a mistake in the figures.
If the gross profit is roughly the same as the comparative but the net profit percentage is vastly down, it can indicate an unusual rise in overheads and can indicate where to look for variances.
Does that help any?
The gross profit is 743,000
The number of suitcases sold is 201,000
The answer, in the answer sheet is 35.45% - however it states this this is for the year ended December, whereas the figures apply to the year ended June 2006.
Baffling ?????