When the dewpoint is 65? Fahrenheit, the relative humidity H is modeled by
H = 4347/400,000,000*e^369,444/(50t + 19,793)

where t is the air temperature in degrees Fahrenheit. Use differentials to approximate the change in relative humidity at t = 70 for a 1-degree change in the air temperature. (Round your answer to two decimal places.)


_________ % per ?F