Chong Corporation recently prepared a flexible budget for water usage at its manufacturing plant. Budgeted water cost at various projected production levels is as follows:

$50,000$ units $ $9,000$

$75,000$ units $13,500$

$90,000$ units $16,200$

Actual units produced amounted to $60,000.$ Actual cost incurred for water usage was $$9,500.$ What was Chong$$s cost variance for water?