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for the following data set calculate the percentage of data points that fall within one standard deviation of the mean, and compare the result to the expected percentage of a normal distribution. {50,46,54,51,29,52,48,54,47,48}

Respuesta :

Answer:

First we need to find the mean and standard deviation of the given data.

The mean and standard deviation are given below:

[tex]Mean=\frac{50+46+54+51+29+52+48+54+47+48}{10}=\frac{479}{10}=47.9[/tex]

[tex]Standard-deviation=\sqrt{\frac{\sum(x-\bar{x})^2}{n-1} }[/tex]

                             [tex]=\sqrt{\frac{(50-47.9)^2+(46-47.9)^2+(54-47.9)^2+...+(48-47.9)^2}{10-1} }[/tex]

                             [tex]=7.20[/tex]

We have:

[tex]\bar{x} \pm s=(47.9 \pm 7.20)[/tex]

                     [tex]=(47.9-7.20, 47.9+7.20)[/tex]

                     [tex]=(40.7, 55.1)[/tex]      

Therefore, the percentage of values that lies within one standard deviation of the mean is:

[tex]\frac{9}{10} \times 100 =90\%[/tex]

The expected percentage of values within one standard deviation of the mean according to normal distribution is 68%.

Therefore, the observed percentage of values within one standard deviation of the mean is much higher than the expected percentage of a normal distribution.