Sodas in a can are supposed to contain an average 12 oz. This particular brand has a standard deviation of 0.1 oz, with an average of 12.1 oz. If the can’s contents follow a Normal distribution, what is the probability that the mean contents of a six-pack are less than 12 oz?

Respuesta :

Answer:

The probability is  [tex]P(X < 12) = 0.99286[/tex]

Step-by-step explanation:

From the question we are told that

        The population mean is [tex]\mu = 12 \ oz[/tex]

         The  standard deviation is  [tex]\sigma = 0.1 \ oz[/tex]

          The sample mean is  [tex]\= x = 12.1 \ oz[/tex]

          The sample size is  n = 6 packs

   

The standard error of the mean is mathematically represented as

              [tex]\sigma_{\= x } = \frac{\sigma}{\sqrt{n} }[/tex]

substituting values

            [tex]\sigma_{\= x } = \frac{0.1}{\sqrt{6} }[/tex]

            [tex]\sigma_{\= x } = 0.0408[/tex]

Given that the can’s contents follow a Normal distribution then then  the probability that the mean contents of a six-pack are less than 12 oz is mathematically represented as

         [tex]P(X < 12) = P ( \frac{X - \mu }{ \sigma_{\= x }} < \frac{\= x - \mu }{ \sigma_{\= x }} )[/tex]

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

So

         [tex]P(X < 12) = P ( Z < \frac{\= x - \mu }{ \sigma_{\= x }} )[/tex]

substituting values

       [tex]P(X < 12) = P ( Z < \frac{12.2 -12 }{0.0408} )[/tex]

      [tex]P(X < 12) = P ( Z < 2.45 )[/tex]

From the normal distribution table the value of [tex]P ( Z < 2.45 )[/tex] is  

           [tex]P (Z < 2.45)0.99286[/tex]

=>   [tex]P(X < 12) = 0.99286[/tex]

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