PSM
Biostatistics
Which statement is true concerning measures of central tendency ? (AIPG 2010)
A  I more outlying observations are smaller than the rest of the values , the data are skewed to the right

B  If more outlying observation is larger than the rest of the values ,the median will be smaller than the mean

C  If the data are skewed to the left , the means is larger than the median

D  The median is more sensitive than the means to extreme observation

When more outlying values are larger than the rest of the values, the data are said to be skewed to the right, and the median is smaller than the mean. If more outlying values are smaller than the rest, the data are said to be skewed to the left, and the median is larger than the mean. The median is more robust than the mean because it is less sensitive to extreme observations and is a more appropriate measure of central tendency when extreme values are part of the data set. The mode, the mean, and the median are all the same for a symmetrical distribution of data. These distributions can be illustrated as follows:
Positively skewed distribution –
Have relatively large number of low scores and small number of very high scores
Mean > median > mode
Negatively skewed distribution –
Have relatively large number of high scores and small number of low scores
Mean < median < mode
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