Measuring Variability in Data: How Many Statistics Do the Job?

This question focuses on identifying statistics that measure the variability of a dataset. Let's analyze each option:

'(i) Sample average': The average provides the central location of a dataset but doesn't directly measure its spread or variability.

'(ii) Sample median': Similar to the average, the median provides the central value, but it doesn't reveal how the data points are distributed around that center.

'(iii) Sample mode': The mode indicates the most frequent value in a dataset, but it doesn't tell us how far other values deviate from it.

'(iv) Sample standard deviation': The standard deviation is a key measure of data variability. It quantifies the spread of values around the mean, giving us a sense of how much data points vary.

Therefore, the answer is d. 3. The following three statistics measure dataset variability: sample median, sample mode, and sample standard deviation.