Correct option is A
· Measures of dispersion are statistical tools used to describe the spread or variability of a dataset.
· Common measures of dispersion include:
· Standard deviation: Indicates how much individual data points deviate from the mean.
· Mean deviation: Measures the average of the absolute deviations from the mean or median.
· Variance: Represents the average squared deviation from the mean.
· Mode, on the other hand, is not a measure of dispersion. It is a measure of central tendency, representing the value that appears most frequently in a dataset.
· Measures of central tendency (mean, median, mode) describe the central point, while measures of dispersion describe the variability around that point.
Thus, the correct answer is (a) Mode.
when the population standard deviation is known, the appropriate test is: