Suppose 52R% of the population has a college degree. If a random sample of size 808808 is selected, what is the probability that the proportion of persons with a college degree will be less than 54T%

Respuesta :

Answer:

The probability is  [tex]P( p < 435.82 ) = 0.54094[/tex]

Step-by-step explanation:

From the question we are told that

   The population proportion is  p =  54% = 0.54

    The sample size is  n  =  808

Generally the distribution of the population with college degree follows a binomial distribution  

i.e  

         [tex]X  \~ \ \ \  B(n , p)[/tex]

Generally the mean is mathematically represented as

       [tex]\mu = n * p[/tex]

=>    [tex]\mu = 808 * 0.52[/tex]

=>    [tex]\mu = 420.16[/tex]

Generally the standard deviation is mathematically represented as

        [tex]\sigma = \sqrt{np(1- p )}[/tex]

=>      [tex]\sigma = \sqrt{808 * 0.52(1- 0.52 )}[/tex]    

=>      [tex]\sigma = 14.2[/tex]

Generally 54% of the population proportion is

         [tex]\^ p = 0.54 * 808[/tex]

=>     [tex]\^ p = 436.32[/tex]

Generally by normal approximation of the binomial distribution the probability that the proportion of persons with a college degree will be less than 54% is mathematically evaluated as

      [tex]P(p < \^ p ) = P(\frac{p - \mu }{\sigma } < \frac{\^ p - \mu }{\sigma } )[/tex]

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

=>  [tex]P(p < 436.32 ) = P( Z < \frac{436.32 - 420.16 }{14.20 } )[/tex]

applying continuity correction

      [tex]P(p < (436.32-0.5) ) = P( Z < \frac{(436.32-0.5) - 420.16 }{14.20 } )[/tex]

=>  [tex]P(p < (435.82 ) = P( Z < \frac{435.82 - 420.16 }{14.20 } )[/tex]

=>  [tex]P(p < (435.82 ) = P( Z < 0.1028 )[/tex]

From the z table  the area under the normal curve to the left corresponding to 0.1028  is

   [tex]P( Z < 0.1028 ) = 0.54094[/tex]

=> [tex]P( p < 435.82 ) = 0.54094[/tex]