An article in the Washington Post on March 16, 1993 stated that nearly 45 percent of all Americans have brown eyes. A random sample of n=82 C of I students found 30 with brown eyes. We test H0:p=.45 Ha:p≠.45 (a) What is the z-statistic for this test? (b) What is the P-value of the test?

Respuesta :

Answer:

The z-statistic for this test is -1.547 and P-value of the test is  0.0618

Step-by-step explanation:

An article in the Washington Post on March 16, 1993 stated that nearly 45 percent of all Americans have brown eyes.

We are given that  A random sample of n=82 C of I students found 30 with brown eyes.

n = 82

x = 30

[tex]H_0:p=0.45\\ H_a:p\neq0.45[/tex]

Now to find z statistic we will use one sample proportion test

[tex]\widehat{p}=\frac{x}{n}[/tex]

[tex]\widehat{p}=\frac{30}{82}[/tex]

[tex]\widehat{p}=0.365[/tex]

Formula of test statistic =[tex]\frac{\widehat{p}-p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]

                                      =[tex]\frac{0.365-0.45}{\sqrt{\frac{0.45(1-0.45)}{82}}}[/tex]

                                      =[tex]-1.547[/tex]

So,  the z-statistic for this test is -1.547

Now refer the z table for p value .

p value = 0.0618

The P-value of the test is  0.0618

Hence the z-statistic for this test is -1.547 and P-value of the test is  0.0618