What is the standard deviation of the following data set rounded to the nearest tenth? 300, 785, 670, 187, 760, 724

We know that
The standard deviation formula  is
s = [Σ(x - μ)²/(n-1)]^(1/2)

step 1
Define the data as the array
x = [300, 785, 670, 187, 760, 724].
The size of the array is n = 6

step 2
find the average
The average is
μ = (300+785+670+187+760+724)/6 = 571

step 3
find x-μ 
x-μ = [-271, 214, 99, -384, 189, 153]

step 4
find (x-μ)²/5
(x-μ)²/5 = [14688, 9159, 1960, 29491, 7144, 4682]
Σ(x-μ)²/5 = 67125

step 5
find s
s =√(67125) = 259.085

the answer is:
259.1 (nearest tenth)