Course / Statistics & Ranking

Mean, median and mode

Find the typical value, and spot when one extreme number is dragging the average. Intermediate · 4 min · MEDIAN, MODE, AVERAGE, ROUND

Ask "what's typical?" and there are three common answers:

• the mean (AVERAGE): add everything up and share it out equally
• the median (MEDIAN): the middle value once the list is sorted
• the mode (MODE): the value that turns up most often

On a well-behaved list the three sit close together. One extreme value, such as a mansion on a street of ordinary homes, can drag the mean a long way while the median barely moves.

Steps

1. Eleven homes sold on Larch Close this year. In F2, work out the mean sale price of C2:C12.

2. In F3, find the median, the middle price once the list is sorted: =MEDIAN(C2:C12)

3. Buyers also want to know the usual house size here. In F6, use MODE on B2:B12 to find the most common number of bedrooms.

4. Nobody quotes house prices to the dollar. In G2, round the mean to the nearest thousand with =ROUND(F2, -3), then fill it down to G3 for the median.

Remember

• AVERAGE shares the total out equally, so a single extreme value can pull it a long way.
• MEDIAN is the middle value and shrugs off outliers: use it for prices, salaries and times.
• MODE is the most common value, handy for counts and sizes.
• ROUND(x, -3) rounds to the nearest thousand for a clean summary.

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