g A random sample of size 16 taken from a normally distributed population revealed a sample mean of 50 and a sample variance of 36. The upper limit of a 95% confidence interval for the population mean would equal:

Respuesta :

Answer:

The  upper limit is    

                   [tex]k = 52.94[/tex]

Step-by-step explanation:

From the question we  told that

     The  sample size is [tex]n = 16[/tex]

      The sample mean is  [tex]\= x = 50[/tex]

      The sample variance is  [tex]\sigma ^2 = 36[/tex]

For  a  95% confidence interval the confidence level is  95%

Given that the confidence level is 95% then the level of significance is  mathematically evaluated  as  

             [tex]\alpha = 100 - 95[/tex]

              [tex]\alpha = 5 \%[/tex]

              [tex]\alpha = 0.05[/tex]

Next we obtain the critical value of  [tex]\frac{\alpha }{2}[/tex] from the normal distribution table(reference- math dot armstrong dot edu), the value is  

              [tex]Z_{\frac{ \alpha }{2} } = 1.96[/tex]

             

Generally the margin of error is mathematically represented as

             [tex]E = Z_{\frac{\alpha }{2} } * \frac{\sigma}{\sqrt{n} }[/tex]

 Here  [tex]\sigma[/tex] is the standard deviation which is mathematically evaluated as

                  [tex]\sigma = \sqrt{\sigma^2}[/tex]

substituting values

                  [tex]\sigma = \sqrt{36}[/tex]

=>                [tex]\sigma = 6[/tex]

So

                    [tex]E = 1.96 * \frac{6}{\sqrt{16} }[/tex]

                     [tex]E = 2.94[/tex]

The 95% confidence interval is mathematically represented as

                 [tex]\= x - E < \mu < \= x + E[/tex]

substituting values

                [tex]50 -2.94 < \mu <50 +2.94[/tex]

                [tex]47.06 < \mu <52.94[/tex]

The  upper limit is    

                   [tex]k = 52.94[/tex]