I have to use a suitable computer package (ie. Excel) to work out the mean and standard deviation of the following:

Price Range No of Houses No of Houses
£`000 Area 1 Area 2
45 and under 50 4 5
50 and under 55 7 12
55 and under 60 14 16
60 and under 70 19 18
70 and under 80 8 3
80 and under 100 5 2

I have used excel to work out mean and standard deviation before, but not in a more complicated example like this.

Any advice on where to start would be greatly appreciated.