Question 468869
Chebyshev's theorem says that at least {{{ 1 - 1/k^2 }}} values will fall within "k" standard deviations of the mean.  For you, that's 3 standard deviations.  The fraction that should fall within 3 standard deviations is therefore {{{ 1 - 1/3^2 = 1-1/9 = 8/9 }}}.  Since we think that 8/9 of the 50 values should fall within 3 standard deviations, we'll multiply: {{{ 50 * (8/9) = 44.44}}}, or about 45 values.