A sample consists of the following scores:
5, 0, 4, 5, 1, 2, and 4.
Compute the mean and standard deviation for the sample. Find the z-score for each score in the sample. Transform the original sample into a new sample with a mean, M = 50 and s = 10.

Respuesta :

Answer:

The sample mean is 3 and the sample standard deviation is 2.

Step-by-step explanation:

The formula to compute the sample mean ([tex]\bar x[/tex]) and sample standard deviation (s)  is:

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

The sample is, S = {5, 0, 4, 5, 1, 2, 4}.

The sample is of size n = 7.

Compute the sample mean value as follows:

[tex]\bar x=\frac{1}{n}\sum x=\frac{1}{7}(5+0+4+5+1+2+4)=3[/tex]

The sample mean is 3.

Compute the sample standard deviation is:

[tex]s=\sqrt{\frac{1}{n-1}\sum (x-\bar x)^{2}} \\=\sqrt{\frac{1}{7-1}[(5-3)^{2}+(0-3)^{2}+(4-3)^{2}+...+(4-3)^{2}]}\\=\sqrt{\frac{1}{6}\times 24}\\=\sqrt{4}\\=2[/tex]

The sample standard deviation is 2.

The formula to compute the z-score of a sample values x is:

[tex]z=\frac{x-\bar x}{s}[/tex]

Compute the z-scores for all the sample values as follows:

  • For x = 5, the z-score is:

        [tex]z=\frac{x-\bar x}{s}=\frac{5-3}{2}=1[/tex]

  • For x = 0, the z-score is:

        [tex]z=\frac{x-\bar x}{s}=\frac{0-3}{2}=-1.5[/tex]

The remaining values are computed similarly in the table.

Now it is provided that the population mean and standard deviation are:

M = 50

S = 10

Transform each z-scores computed, into new sample values using the formula:

[tex]z=\frac{X-M}{S}\\z=\frac{X-50}{10}\\X=10z+50[/tex]

The new sample values are computed in the table below.

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