Mean, Median,Mode
The total blood cholesterol level was measured for each of 21adults. Here are the 21 measurements (in mg/dL). 129, 144, 159, 162, 163, 168, 183, 184, 184, 185, 186, 195, 196, 197, 198, 207, 209, 221, 222, 234, 246.(a) Which measures of central tendency do not exist for this data set? Choose all that apply.
Mean
Median
Mode
None of these measures
(b) Suppose that the measurement 129 (the smallest measurement in the data set) were replaced by 52. Which measures of central tendency would be affected by the change? Choose all that apply.
Mean
Median
Mode
None of these measures
(c) Suppose that, starting with the original data set, the smallest measurement were removed. Which measures of central tendency would be changed from those of the original data set? Choose all that apply.
Mean
Median
Mode
None of these measures
(d) Which of the following best describes the distribution of the original data? Choose only one.
Negatively skewed
Positively skewed
Roughly symmetrical
Sample Answer
(a) The mean and median do not exist for this data set. The mean is not defined because there is an even number of data points and the median is not defined because the data points are not arranged in increasing order. The mode is 184, which is the most frequent data point.