The amount of nitrogen dioxide, a brown gas that impairs breathing, present in the atmosphere on a certain may day in the city of long beach is approximated by

a(t) = 136/1+ 0.24(t − 4.5)^2 + 28 (0 ≤ t ≤ 11) where a(t) is measured in pollutant standard index (psi) and t is measured in hours, with t = 0 corresponding to 7 a. m. determine the time of day when the pollution is at its highest level.

Which of these is and example of a literal equation? a) 6+30=6^2 b)3x-4y c)12=9+3x d)ax-by=k

Compare the following pair of numbers a and b in three ways. a. find the ratio of a to b. b. find the ratio of b to a. c. complete the sentence: a is percent of b. a=120 and b=340 a. the ratio of a to b is . b. the ratio of b to a is . c. a is nothing percent of b.

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.