A very large data set (N > 10,000) has a mean value of 2.06 units and a standard deviation of 55.85 units. Determine the range of values in which 50% of the data set should be found assuming normal probability density (find ux in the equation xi = x' ± ux).

Respuesta :

Answer:

 So in range "-35.6108 to 39.73"; 50% data set can be found

ux = 37.6704 unites

Step-by-step explanation:

Step One: State the given parameters

From the question we are given that

mean Ц =2.06 unites

Standard deviation б is  = 55.85 unites  

Probability density  → Normal

Let assume that it is symmetrically distributed about the mean

Step Two: Determine the range of the values

Our goal is to determine the range of values in which 50% of the data set should be found . Assuming that the range is from [tex]x_{1}[/tex] to [tex]x_{2}[/tex] and between these these we found 50% data set Hence from 0 up to [tex]x_{1}[/tex] we found 25% and up to [tex]x_{2}[/tex]  we found 75% of the data set therefore z value corresponding to [tex]x_{1}[/tex] is - 0.6745 and the the z value corresponding to [tex]x_{2}[/tex] is +0.6745 (Refer to the z-table for normal distribution) as shown o the diagram on the first uploaded image

The formula for  z is

                    z = [tex]\frac{x-mean}{standard deviation}[/tex]

for [tex]x_{1}[/tex] ,z = - 0.6745 ,substituting into the formula

               [tex]-0.6745 = \frac{x_{1}-2.06}{55.85}[/tex]

 => -37.67 =  [tex]x_{1}[/tex] -2.06

=> [tex]x_{1}[/tex] =  -35.6108 unites  

for [tex]x_{2}[/tex]  , z = 0.6745 , substituting into the formula

            [tex]0.6745 = \frac{x_{2}-2.06}{55.85}[/tex]

=> 37.67 =  [tex]x_{2}[/tex]  -2.06

=>  [tex]x_{2}[/tex]  = 39.73 units

 So in range "-35.6108 to 39.73"; 50% data set can be found

ux = (39.73  -   (-35.73) )/2

   = 37.6704 unites

Ver imagen okpalawalter8