Question: Calculate the average review star from users in businesses located in South Carolina and California state.
SQL: SELECT 1.0 * (( SELECT SUM(T1.stars) FROM Business AS T1 INNER JOIN Reviews AS T2 ON T1.business_id = T2.business_id WHERE T1.state = 'SC' ) + ( SELECT SUM(T1.stars) FROM Business AS T1 INNER JOIN Reviews AS T2 ON T1.business_id = T2.business_id WHERE T1.state = 'CA' )) / ( SELECT SUM(T1.stars) FROM Business AS T1 INNER JOIN Reviews AS T2 ON T1.business_id = T2.business_id ) AS reslut