Why following answers are don't become same?

I think there are two variance's formula (using freq and probability) and I tried to use both, but two answers are not same.

Information P Flag question Twenty-one randomly selected students were asked the number of pairs of sneakers they owned. The number of pairs of sneakers owned by each student was recorded in an R object by the name "x". The frequency table of the data "x" is: > table(x) x 2 3 3 2 2 Based on this table compute: Question 36 Not answered Marked out of 1.00 P Flag question The sample standard deviation (s) is Answer: Run the code: > x. val freq rel. freq x.bar var.x sqrt(var.x) [1] 1.609496 The correct answer is: 1.609496> X = c(1,2,3,4,5,6) > freq = c(4,7,3,3,2,2) > rel = freq/sum(freq) > mu = sum(x*rel) > var = sum((x-mu)^2*rel) > sig = sqrt(var) > sig [1] 1.570707