Write SQL query to solve given problem: What is the average number of reviews of all the root beer brands from "CA" State?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CAST(COUNT(*) AS REAL) / COUNT(DISTINCT T1.BrandID) AS avgreview FROM rootbeerbrand AS T1 INNER JOIN rootbeerreview AS T2 ON T1.BrandID = T2.BrandID WHERE T1.State = 'CA'