Annual starting salaries for college graduates with degrees in business administration are generally expected to be between $30,000 and $45,000 with a population standard deviation of $3750. Assume that a 95% confidence interval estimate of the population mean annual starting salary is desired. How large a sample should be taken if the desired margin of error is $200?

Respuesta :

Answer:

The value is   [tex]n =1351 [/tex]

Step-by-step explanation:

From the question we are told that

  The standard deviation is  [tex]\sigma = \$3750[/tex]

   The margin of error is  [tex]E = \$ 200[/tex]

From the question we are told the confidence level is  95% , hence the level of significance is    

      [tex]\alpha = (100 - 95 ) \%[/tex]

=>   [tex]\alpha = 0.05[/tex]

Generally from the normal distribution table the critical value  of  [tex]\frac{\alpha }{2}[/tex] is  

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

Generally the sample size is mathematically represented as

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

=>      [tex]n = [1.96  *  3750 }{200} ] ^2[/tex]

=>      [tex]n =1351 [/tex]