This is probably embarrassingly simple but: How do I divide one row with another?

One row contains hours, another the number of hits. How do I calculate the number of hours spent for each 'hit', i.e. hours / hits?

I have used Tableau's reshape data add-in for Excel to put the dimensions in one column and all values (for the different dimensions) in another column. That makes good sense until I need to seperate out the hours values from the value column and divide it with the hits values from the values column... With this setup the support on calculated fields does not make sense, as I do not have a field called 'Hours' or 'Hits'.

Hope I'm making sense, and yes, I have checked tutorials and the support forum ;-)

Any help appreciated!

Albert