Urgh, that was a shock. I needed to add a column of fractions, like this:
- 1/4
- 1/4
- 1/10
- 1/10
- 1/25
- 1/25
- 1/25
I quickly realised I had not the faintest idea how to do it! Thank goodness for spreadsheets.
An online calculator then converted the sum to a decimal. Hooray!