I need a detailed answer on how to solve this question, with steps so I can learn to do it myself.

Today, Stock A is worth $20 and has 1,000 shares outstanding. Stock B costs $30 and has 500 shares outstanding. Stock C is priced at $50 per share and has 1,200 shares outstanding. If, tomorrow, Stock A is priced at $22, Stock B at $35, and Stock C is worth $48, what would the value-weighted index amount equal? (The index has a base period value of 100.)