## Chemistry and Chemical Reactivity (9th Edition)

$\bar{x}=5.24\%$ $\sigma = 0.053\%$ 7
The average is given by: $\bar{x}=\frac{\sum x_i}{n}$, from the 10 values reported the average is: $\bar{x}=5.24\%$ The standard deviation is given by: $\sigma = \sqrt{\dfrac{\sum(x_i-\bar{x})^2}{n-1}}$, which leads to the value of: $\sigma = 0.053\%$ 7 out of 10 student's results are within the range of $5.19\%-5.29\%$ (one standard deviation away from the average).