A mini wind tunnel for calibrating vane or hotwire anemometers cost $3750 in 2002 when the M&S

Question:

A mini wind tunnel for calibrating vane or hotwire anemometers cost $3750 in 2002 when the M&S equipment index value was 1104.2. If the index value is now 1620.6, estimate the cost of a tunnel twice as large. The cost-capacity equation exponent is 0.89.