4r + 9r- 11r +7r
simfly the expressions by combing like terms? ?

The thickness of photoresist applied to wafers in semiconductor manufacturing at a particular location on the wafer is uniformly distributed between 0.2070 and 0.2171 micrometers.(a) determine the proportion of wafers that exceeds 0.2125 micrometers of photoresist thickness. (round your answer to 3 decimal places.)enter your answer in accordance to the item a) of the question statement(b) determine the mean of x. (round your answer to 4 decimal places.)enter your answer in accordance to the item b) of the question statement micrometers(c) determine the variance of x. (round your answer to 8 decimal places.)enter your answer in accordance to the item c) of the question statement micrometers2