Measures of Central Tendency Test Prep AK

1. C. The median is a middle score and is not strongly affected by outliers.  The mean can be dragged down or up by very low or very high numbers.  Because the mean is lower than the median, there are probably some very low scores in the mix, pulling the average down. 

2. B. The mode of the data is \$67.88, and changing \$12.99 to \$122.99 does not affect that. The range of the data will not change because neither the highest nor the lowest number in the data set has changed.  The mode will not change.  The mean will change because changing any datapoint will change the mean.  The median will change because a low number (below the median) is being changed to a high number (above the median) which will shift the median down a datapoint.

3. D. By removing the Anatomy books, you are removing two high datapoints (above the median).  Removing those datapoints will push the median down. 

4. B. There is only one mode of the dataset: \$67.88.  But, removing the accounting books removes one of the \$67.88 datapoints, which means that there is not longer a mode of this dataset. 

5. B. There are some low earners bringing the mean down, but not too many of them (if there were a lot of them, it would bring the median down too).