Calculate the average review star from users in businesses located in South Carolina and California state.
"South Carolina" and "California" are both state; average review stars from users = Divide((Sum(review_stars(state = 'SC')) + Sum(review_stars(state = 'CA'))), Sum(stars))
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