Compute the total of two variables

[Jorge Martin]

Hi Everyone,

I have a dataset with two variables: one for all cars and another specifically for BMW cars. I would like to compute the percentage of BMW cars compared to the total number of cars. How can I do that? I only need the total percentage of the BMW cars

[Nick Cox]

I can think of several datasets loosely consistent with this description. The moral is that nothing beats a good data example showing us variable names, storage types, data layout and so forth.

Please read https://www.statalist.org/forums/help#stata and then give us a data example using dataex.