Arturo Muina is the captain of a charter fishing boat. He is paid a salary of $140 per day. He also averages tips amounting to 12% of a $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 = 3,080 >> base salary

22 * 475 * 0.12 = ? >> tips

Add the tips to the base salary.

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

First, let's calculate Arturo's salary. Since he is paid $140 per day and worked for 22 days, his salary for the month can be calculated as follows:
Salary = Daily Rate x Number of Days
Salary = $140/day x 22 days = $3,080

Next, let's calculate Arturo's tips. Since he receives tips amounting to 12% of the $475 daily charter rate, we can calculate his tips for each day as follows:
Tips = 12% of Daily Charter Rate
Tips = 0.12 x $475 = $57

Now, we can calculate Arturo's total tips for the month by multiplying his daily tips by the number of days he worked:
Total Tips = Tips per Day x Number of Days
Total Tips = $57/day x 22 days = $1,254

Finally, we can calculate Arturo's total gross earnings by adding his salary and tips:
Total Gross Earnings = Salary + Total Tips
Total Gross Earnings = $3,080 + $1,254 = $4,334

Therefore, Arturo's total gross earnings for the month amount to $4,334.