Question

the mean and standard deviation would be the best measure of center and spread for which distribution below? none of these

Explanation:

The mean and standard deviation are the best measures of center and spread for symmetric distributions. The third histogram (the one with a peak in the middle and decreasing frequencies on both sides) is symmetric. The first two histograms are skewed (the first is skewed right and the second is skewed left). For skewed distributions, the median and inter - quartile range are more appropriate measures of center and spread.

Answer:

The third distribution (the symmetric one).