Calculate Productivity

I'm having trouble calculating productivity using time variables in multiple columns. Here is my layout

A1 (Hours for an entire month) 389 (formated as a number 0.00)
A2 (Minutes for an entire month) 59 (formated as a number 0.00)

Note: Minutes will never exceed 59

A3 (Number of stops a driver made during the month) 430 (formatted as a number 0.00)

I'm looking to calculate the drivers stops per hour for the month in A4

Thx