Alright, lets get started.
The Denver office has 137 employees with an average salary of $67,013.
So the total salay of all employees at Denver office will be = 
So the total salay of all employees at Denver office will be = $ 9180781
The Anchorage office has 25 employees with an average salary of $71,332.
So the total salary of employees at Anchorage office will be = 
So the total salary of employees at Anchorage office will be = $ 1783300
So, complete total salary of employees at both offices will be = 
So, complete total salary of employees at both offices will be = $ 10964081
Total number of employees at both offices are = 
So, the average salary of employee across the company = 
So, the average salary of employee across the company = 67679.5
Rounding off,
So, the average salary of employee across the company = $ 67680 : Answer
Hope it will help :)