9 The histogram shows information about the numbers of cars in five different price ranges, sold in one year at a car showroom.
\includegraphics[max width=\textwidth, alt={}, center]{4ba60d6b-c987-4f6b-8c55-8b594c90c854-06_922_1413_495_244}
It is given that 66 cars in the price range \(\pounds 10000\) to \(\pounds 20000\) were sold.
- Find the number of cars sold in the price range \(\pounds 50000\) to \(\pounds 90000\).
- State the units of the frequency density.
- Suggest one change that the management could make to the diagram so that it would provide more information.
- Estimate the number of cars sold in the price range \(\pounds 50000\) to \(\pounds 60000\).