A company has a custom object, Sales, }_Help_Request__c, that has a Lookup relationship to Opportunity. The Seles Help Request__c has a mumber field, Number_ct_Hours__c, that represents the amount of time spent on the Sales_Help Request__C.
A developer is tasked with creating a field, total_Hour2__c, on Opportunity that should be the sum of all of the Number_of_Hours_c values for the Sales_Help_Request__c records related to that Opportunity.