A survey of 23 retirees was taken. Among other things, the retirees were asked to report the age at which they retired. Here are those 23 ages (in years):

39, 49, 49, 49, 51, 53, 55, 58, 62, 63, 66, 66, 66, 66, 67, 68, 68, 68, 72, 73, 75, 75, 78.

(a) Which measures of central tendency do not exist for this data set? Choose all that apply.

MeanMedianModeNone of these measures

(b) Supposes that the measurement 78 (the largest measurement in the data set) were replaced by 86. Which measures of central tendency would be affected by the change? Choose all that apply.MeanMedianModeNone of these measures

(c) Supposes 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? Choose all that apply.MeanMedianModeNone of these measures

(d) Which of the following best describes the distribution of the original data? Choose only one.Negatively skewedPositively skewedRoughly symmetrical