1. A survey of 3300 people asked them whether they liked blueberry pie. Suppose that the people were all chosen independently with a 99.98% chance of liking blueberry pie. (a) Why is the normal approximation not appropriate in this instance? (b) Calculate the probability that all 3300 people will say they like blueberry pie. (c) Use a Poisson approximation to find the probability that 3297 of the people will say that they like blueberry pie.

Respuesta :

Answer:

a

normal approximation not appropriate in this instance because  

    [tex]np = 3300 * 0.9998 = 3299.3 > 5[/tex]

and  

     [tex]nq = 3300 * 0.0002 = 0.66 < 5[/tex]

b

  The probability is  [tex]P(X = 3300) = 0.52[/tex]

c

 The probability is  [tex]P(X = 3287) = 0[/tex]

Step-by-step explanation:

From the question we are told that

   The  sample size is  [tex]n = 3300[/tex]

    The  chance of liking blueberry pie is  [tex]p = 0.9998[/tex]

    The  chance of not  liking blueberry pie is [tex]q = 0.0002[/tex]

For normal approximation is possible if  

       [tex]np > 5[/tex] , [tex]nq > 5[/tex]

Now let test

      [tex]np = 3300 * 0.9998 = 3299.3 > 5[/tex]

and  

     [tex]nq = 3300 * 0.0002 = 0.66 < 5[/tex]  

The  probability that all 3300 people will say they like blueberry pie is mathematically represented as

       [tex]P(X = 3300) = p^{3300}[/tex]

       [tex]P(X = 3300) = (0.9998)^{3300}[/tex]

        [tex]P(X = 3300) = 0.52[/tex]

The probability that 3297 of the people will say that they like blueberry pie is  mathematically represented as

         [tex]P(X = 3287) = \frac{(np)^{3297! } * e^{-np}}{3297}[/tex]

          [tex]P(X = 3287) = \frac{0}{\infty}[/tex]

          [tex]P(X = 3287) = 0[/tex]