The heights of North American women are nor-mally distributed with a mean of 64 inches and a standard deviation of 2 inches. a. b. c. What is the probability that a randomly selected woman is taller than 66 inches? A random sample of four women is selected. What is the probability that the sample mean height is greater than 66 inches? What is the probability that the mean height of a random sample of 100 women is greater than

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Complete Question

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Answer:

a

  [tex]P(X > 66) = P(Z> 1 ) = 0.15866[/tex]

b

[tex]P(\= X > 66) = P(Z> 2 ) = 0.02275[/tex]

c

[tex]P(\= X > 66) = P(Z> 10 ) = 0[/tex]

Step-by-step explanation:

From the question we are told that

   The  population mean is  [tex]\mu = 64 \ inches[/tex]

    The standard deviation is  [tex]\sigma = 2 \ inches[/tex]

The probability that a randomly selected woman is taller than 66 inches   is mathematically represented as

    [tex]P(X > 66) = P(\frac{X - \mu }{\sigma } > \frac{ 66 - \mu }{\sigma} )[/tex]

Generally [tex]\frac{ X - \mu }{\sigma } = Z(The \ standardized \ value \ of \ X )[/tex]

So  

      [tex]P(X > 66) = P(Z> \frac{ 66 - 64 }{ 2} )[/tex]

     [tex]P(X > 66) = P(Z> 1 )[/tex]

From the z-table  the value of  [tex]P(Z > 1 ) = 0.15866[/tex]

 So  

       [tex]P(X > 66) = P(Z> 1 ) = 0.15866[/tex]

Considering b

 sample mean is  n  =  4  

Generally the standard error of mean is mathematically represented as

        [tex]\sigma _{\= x} = \frac{\sigma }{\sqrt{4} }[/tex]

=>    [tex]\sigma _{\= x} = \frac{2 }{\sqrt{4} }[/tex]

=>    [tex]\sigma _{\= x} = 1[/tex]

The probability that the sample mean height is greater than 66 inches    

     [tex]P(\= X > 66) = P(\frac{X - \mu }{\sigma_{\= x } } > \frac{ 66 - \mu }{\sigma_{\= x }} )[/tex]

=>   [tex]P(\= X > 66) = P(Z > \frac{ 66 - 64 }{1} )[/tex]

=>  [tex]P(\= X > 66) = P(Z> 2 )[/tex]

From the z-table  the value of  [tex]P(Z > 2 ) = 0.02275[/tex]

=> [tex]P(\= X > 66) = P(Z> 2 ) = 0.02275[/tex]

Considering b

 sample mean is  n  =  100

Generally the standard error of mean is mathematically represented as

        [tex]\sigma _{\= x} = \frac{2 }{\sqrt{100} }[/tex]

=>    [tex]\sigma _{\= x} = 0.2[/tex]

The probability that the sample mean height is greater than 66 inches

   [tex]P(\= X > 66) = P(Z > \frac{ 66 - 64 }{0.2} )[/tex]

=>  [tex]P(\= X > 66) = P(Z> 10 )[/tex]

From the z-table  the value of  [tex]P(Z > 10 ) = 0[/tex]

[tex]P(\= X > 66) = P(Z> 10 ) = 0[/tex]

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