"Assume the average price of a laptop computer is ​$775 with a standard deviation of ​$75. The following data represent the prices of a sample of laptops at an electronics store. Calculate the​ z-score for each of the following prices"
a. $699
b. $949
c. $625
d. $849
e. $999

Respuesta :

Answer:

(a) -1.0133

(b) 2.32

(c) -2

(d) 0.9867

(e) 2.9867

Step-by-step explanation:

The z-score of a raw score X is a standardized score that follows a normal distribution with mean 0 and standard deviation 1.

The formula to compute the z-score is:

                       [tex]z=\frac{x-\mu}{\sigma}[/tex]

Given:

Mean (μ) = $775

Standard deviation (σ) = $75

(a)

For X = $699 the z-score is:

[tex]z=\frac{x-\mu}{\sigma}\\=\frac{699-775}{75} \\=-1.0133[/tex]

(b)

For X = $949 the z-score is:

[tex]z=\frac{x-\mu}{\sigma}\\=\frac{949-775}{75} \\=2.32[/tex]

(c)

For X = $625 the z-score is:

[tex]z=\frac{x-\mu}{\sigma}\\=\frac{625-775}{75} \\=-2[/tex]

(d)

For X = $849 the z-score is:

[tex]z=\frac{x-\mu}{\sigma}\\=\frac{849-775}{75} \\=0.9867[/tex]

(e)

For X = $999 the z-score is:

[tex]z=\frac{x-\mu}{\sigma}\\=\frac{999-775}{75} \\=2.9867[/tex]

Answer:

a) -1.013

b) 2.32

c) -2

d) 0.9867

e) 2.9867                                              

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = $775

Standard Deviation, σ = $75

We are given that the distribution of  average price of a laptop is a bell shaped distribution that is a normal distribution.

Formula:

[tex]z_{score} = \displaystyle\frac{x-\mu}{\sigma}[/tex]

We have to find z-score for corresponding

a. $699

[tex]z = \displaystyle\frac{699 - 775}{75} = -1.013[/tex]

b. $949

[tex]z = \displaystyle\frac{949 - 775}{75} = 2.32[/tex]

c. $625

[tex]z = \displaystyle\frac{625 - 775}{75} = -2[/tex]

d. $849

[tex]z = \displaystyle\frac{849 - 775}{75} = 0.9867[/tex]

e. $999

[tex]z = \displaystyle\frac{999 - 775}{75} = 2.9867[/tex]