A council reviews the number of bedrooms in 40 houses located in the same area. The table shows the information gathered. Find the modal average number of bedrooms. Work out the mean number of bedrooms

Mode is the most frequent number, in this case, 3 bedrooms appears 15 times. As a result 3 is the mode.
Doing the mean, is the same as providing a weighted average of bedrooms, with the weights being the frequency a given number of bedrooms appears at. As such, I need to multiply each element of the first column with the respective element of the second column. For example, for 1 bedroom, I have 1 x5 = 5; for 2 bedrooms I have 2x10 =20; if we do this across all number of bedrooms, and then add it all up, we get 113. We then divide this 113, by the number of flats being surveyed ie 40. This gives an average (or mean) of 2.825