Can Anyone explain it step by step without excel formula. Thanks

17) 17) Sun Corporation has had returns of -6 percent, 16 percent, 18 percent, and 28 percent for the past four years. Calculate the standard deviation of the returns using the correction for the loss of a degree of freedom shown below. When variance is estimated from a sample of observed returns, we add the squared deviations and divide by N-1, where N is the number of observations. We divide by N -1 rather than N to correct for a loss of a degree of freedom. The formula is N Variance (rm) = 1 N-1 2 m-rm)2. t=1 Where m is the market return in period t and rm is the mean of the values of rmt A) 14.0 percent B) 11.6 percent C) 13.4 percent D) 14.3 percent