Mathematics

Kathy Moyer

10 September, 23:32

The Air Quality Index, or AQI, measures how polluted the air is in your city and assigns a number based on the quality of the air. Over 100 is "Unhealthy".

The following quadratic regression equation, models the AQI over time, where n represents the number of days the AQI exceeded 100, and t represents the number of years since 1990.

Estimate the number of days the AQI exceeded 100 in the year 2002. Round to the nearest whole day. (Hint: t = 0 corresponds to the year 1990.)

a.

281 days

b.

97 days

c.

135 days

d.

52 days