Answer
$\approx1.49$
Work Step by Step
The mean of $n$ numbers is the sum of the numbers divided by $n$.
Hence the mean: $\frac{6+6+6+6+7+7+7+4+8+3 }{10}=6$
The standard deviation of $x_1,x_2,...,x_n$ is (where $\overline{x}$ is the mean of the data values): $\sqrt{\frac{(x_1-\overline{x})^2+(x_2-\overline{x})^2+...+(x_n-\overline{x})^2}{n-1}}$.
Hence here the the standard deviation is: $\sqrt{\frac{4(6-6)^2+3(7-6)^2+(4-6)^2+(8-6)^2+(3-6)^2}{10-1}}\approx1.49$
