Standard Deviation
The standard deviation for a sample of size n is given by:
[tex]\sigma=\sqrt[]{\frac{\sum ^{}_{}(x_i-\bar{x})^2}{n-1}}[/tex]
Where xi represents each value of the sample, x(bar) is the mean of all the values, and n is the number of values of the sample.
For the convertible models, the values are:
25, 25, 24, 21, 21, 21, 20
The mean value is:
[tex]\begin{gathered} \bar{x}=\frac{25+25+24+21+21+21+20}{7} \\ \bar{x}=\frac{157}{7} \\ \bar{x}=22.4286 \end{gathered}[/tex]
The calculations involved in this formula are too long to display here, so we show the result:
[tex]\sigma=2.149[/tex]
Following the same procedure for the sport models:
[tex]\begin{gathered} \bar{x}=\frac{23+24+21+18+21+25+27}{7} \\ \bar{x}=\frac{159}{7} \\ \bar{x}=22.7143 \end{gathered}[/tex]
The second standard deviation is:
[tex]\sigma=2.9841[/tex]
