Calculating average salary by city and gender

Hello,

I am a behavioural strategist from South Africa working within the financial services industry. My work involves helping employees make better financial decisions which means developing easily read dash boards of statistics to present to company directors in order to implement new policy.

I have a dataset of financial data from different companies and cities and I want to get a macro view of what each group is doing. I individual salary details, the city and gender of each individual. I am trying to calculate a total average salary for males in (for example) johannesburg. Can anyone help?????