Guadalajara Tours' daily sightseeing trip has a capacity of 55 people. Each day, tour officials record the number of people making the trip. The data for a selection of 21 summer days are as follows. 31, 37, 41, 42, 42, 44, 46, 47, 48, 48, 48, 49, 51, 51, 51, 51, 52, 52, 52, 53, 54 (a) Which measures of central tendency do not exist for this data set? mean, medium, mode, or none of these measures. Choose all that apply. (b) Suppose that the measurement 31 (the smallest measurement in the data set) were replaced by 15. Which measures of central tendency would be affected by the change? Mean, median, mode or none these measures. Choose all that apply. (c) Suppose that, starting with the original data set, the largest measurement were removed. Which measures of central tendency would be changed from those of the original data set? Mean, median, mode or none of these measures. Choose all that apply.