An intelligence test was recently administered to a group of 9 people. Their respective completion times (in minutes) were as follows. 29, 40, 38, 38, 31, 37, 31, 38, 31 Send data to calculator Send data to Excel (a) What is the mean of this data set? If your answer is not an integer, round your answer to one decimal place. (b) What is the median of this data set? If your answer is not an integer, round your answer to one decimal place. (c) How many modes does the data set have, and what are zero modes their values? Indicate the number of modes by clicking in the appropriate circle, and then indicate the value(s) of the one mode: mode(s), if applicable. two modes: [and X