In reporting the frequency distribution of annual household income, the Statistical Abstract of the United States uses these class intervals: under $10,000; $10,000-14,999; $15,000-24,999; $25,000-34,999; $35,000- 49,999; $50,000-74,999; and $75,000 and over. Which measures of variability could we compute for the distribution as given in terms of those class intervals?