What action should be taken to increase the values in the 'CreditHourFee' field by 25%?

To increase the values in the 'CreditHourFee' field by 25%, running an update query with the expression '[CreditHourFee]*1.25' is the correct action. This type of query directly modifies the existing records in the database. The expression multiplies the current value of 'CreditHourFee' by 1.25, effectively increasing it by 25%.

This method is efficient because it targets the specific field that needs adjustment and applies the change to all records in one operation, ensuring consistency. In contrast, other actions like deleting records, running a select query, or appending new records do not achieve the goal of modifying the existing fee values as required. Deleting records would remove data, a select query would only display data without modifications, and an append query would add new records instead of adjusting existing ones. Hence, using an update query is the most straightforward and appropriate solution for increasing the values in the specified field.