18. A man buys two tables for Rs 900. He sells one at a loss of 10% and the other at a gain of 2% On the whole transaction he neither gains nor loses. Find the cost price of each table.

an advantage of the standard deviation is that it increases as the dispersion of the data increases. e. the interquartile range is preferred when the data are not skewed or no have outliers. an advantage of the standard deviation is that it uses all the observations in its computation.