Need help with 7,8 & 9

What is the interquartile range of this data set? 2, 5, 9, 11, 18, 30, 42, 48, 55, 73, 81

18 16 11 45 33 11 33 14 18 11 what is the mode for this data set

The human resources manager at a company records the length, in hours, of one shift at work, x. he creates the probability distribution below. what is the probability that a worker chosen at random works at least 8 hours? 0.62 0.78 0.84 0.96