Consumers often object to price changes in many daily products, even though inflation and other cost changes may justify these increases. To reduce the resistance to a price increase, many manufacturers adjust both prices and product sizes at the same time. For example, the regular selling price for a bottle of shampoo was $10 for 1 litre. To account for cost changes, the manufacturer decided to change the price to $ 8.50, but also reduce the bottle size to 800 millilitres. What was the percent change in the price per millilitre? Round your answer to two decimal places, and do not include % sign in your