A one-question survey is to be distributed to a random sample of 1500 adults in Ohio. The question asks if they support an increase in the state sales tax from 5% to 6%, with the additional revenue going to education. Let p-hat denote the proportion of adults in the sample who say they support the increase. Suppose that 40% of all adults in Ohio support the increase. What is the probability that p-hat will be more than 50%

Respuesta :

Solution :

It is given that :

Total number of adults in the sample of Ohio, n = 1500

Increase in the sale tax = 5% to 6 %

Let [tex]$\hat p$[/tex] = proportion of the adults that supported the increase in the sales tax.

        = 40%

        = 0.40

Therefore the probability that [tex]$\hat p$[/tex]  will be more than 50% will be :

   [tex]$P(\hat p > 0.50) = P\left( \frac{\hat p - E(\hat p)}{\sigma_{\hat p}} > \frac{0.50-0.40}{0.0123}\right)$[/tex]

                    [tex]$=P(z>7.936508)$[/tex]

                    [tex]$=1-P(Z<7.936508)$[/tex]

                    = 1 - 1

                    = 0