Answer
See below.
Work Step by Step
The mean of $n$ numbers is the sum of the numbers divided by $n$. The median of $n$ is the middle number of the numbers when they are in order (and the mean of the middle $2$ numbers if $n$ is even). The mode of $n$ numbers is the number or numbers that appear(s) most frequently.
Hence here the mean is: $\frac{75+76+79+85+88+88+90+92}{8}=84.125$. The median is the mean of the middle items in the sequence $75, 76, 79, 85, 88, 88, 90, 92$, which is: $(85+88)/2=86.5$. The mode is $88$.
The range is the difference between the largest and the smallest data value. The standard deviation of $x_1,x_2,...,x_n$ is (where $\overline{x}$ is the mean of the data values): $\sqrt{\frac{(x_1-\overline{x})^2+(x_2-\overline{x})^2+...+(x_n-\overline{x})^2}{n}}$.
Hence here the range is: $92-75=17$ and the standard deviation is: $\sqrt{\frac{(75-84.125)^2+(76-84.125)^2+...+(92-84.125)^2}{8}}\approx6.2$
