select department, ifnull(round(avg(normal_salary - dock_salary),2),0.00) average_actual_salary, ifnull(round(sum(if(staff_gender = 'male',normal_salary - dock_salary,0))/sum(if(staff_gender = 'male',1,0)),2),0.00) average_actual_salary_male, ifnull(round(sum(if(staff_gender = 'female',normal_salary...