Arturo Muina is the captain of a charter fishing boat. He is paid salary of 140 per day He also averages tips amounting to 12% of 475 daily charter rate. Last month during a fishing tournament, Arturo worked 22 days. What were his total gross earnings for the month?

22(140 + .12(475) = ?

To calculate Arturo's total gross earnings for the month, we need to consider his salary and average tips.

Step 1: Calculate Arturo's salary earnings:
Arturo's salary per day is $140, and he worked for 22 days.
Salary earnings = $140/day * 22 days = $3080

Step 2: Calculate Arturo's average tips earnings:
Arturo's average tips amount to 12% of the daily charter rate.
The daily charter rate is $475, so the average tips per day = 12% * $475 = $57

Now, we need to calculate the total tips earned by multiplying the average tips per day by the number of days worked:
Total tips earnings = $57/day * 22 days = $1254

Step 3: Calculate Arturo's total gross earnings:
Total gross earnings = Salary earnings + Tips earnings
Total gross earnings = $3080 + $1254 = $4334

Therefore, Arturo's total gross earnings for the month were $4334.