How do you write the exponent of normal distribution mu sigm

How do you write the exponent of normal distribution (mu, sigma) in terms of sample mean and variance for iid x1, x2, x3,....xn . That means no more summation X and summation x².

Solution

mu = ( x1 + x2 + x3+ ... + xn)/n

sigma = sqrt[ ( (x1-mean)^2 + (x2-mean)^2 + (x3-mean)^2 + ... +(xn-mean)^2 )/n-1 ]