Can we automatically fill in Region based on information entered in State field

Can we automatically fill in Region based on information entered in State field

Our team is segmented into regions based on states and in Zoho we have both a "State" field and a "Region" Field. 

Is it possible to create a rule or some time of automation that if, for example, I were to enter "AZ" into the "State" field, the "Region" field would automatically populate to "Southwest"?