A new electrostatic precipitator has been requested to clean the air of

a new work area. A complete package unit with a capacity of $5\mathrm{.}7$

cubic meters per second was recently purchased for $$85,000.$ The

new unit needs to be twice that size.

$($a$)$ Use the data in Table $21$ to estimate the cost of the new

electrostatic precipitator.

$($b$)$ Electrostatic precipitators do a good job at cleaning the air, but

they use a lot of electricity. Are they thought to be environmentally

friendly?