Calculate the average rate of change of the given function over the given interval. Where appropriate, specify the units of...

Calculate the average rate of change of the given function over the given interval. Where appropriate, specify the units of measurement. HINT [See Example 1.] Interval: [2, 6] . ---Select--- dollars per day months per dollar dollars per year dollars per month years per dollar . t (months) 2 4 6 R(t) ($ millions) 20.5 24.6 19.9