In a recent survey of drinking laws, a random sample of 1000 women showed that 65% were in favor of increasing the legal drinking age. In a random sample of 1000 men, 60% favored increasing the legal drinking age. Test the claim that the percentage of men and women favoring a higher legal drinking age is different at (alpha 0.05).

Respuesta :

Answer:

Step-by-step explanation:

Given that:

Let sample size of women be [tex]n_1[/tex]  = 1000

Let the proportion of the women be [tex]p_1[/tex] = 0.65

Let the sample size of the men be [tex]n_2[/tex] = 1000

Let the proportion of the mem be [tex]p_2[/tex]  = 0.60

The null and the alternative hypothesis can be computed as follows:

[tex]H_0: p_1 = p_2[/tex]

[tex]H_0a: p_1 \neq p_2[/tex]

Thus from the alternative hypothesis we can realize that this is a two tailed test.

However, the pooled sample proportion p = [tex]\dfrac{p_1n_1+p_2n_2 } {n_1 +n_2}[/tex]

p =[tex]\dfrac{0.65 * 1000+0.60*1000 } {1000 +1000}[/tex]

p = [tex]\dfrac{650+600 } {2000}[/tex]

p = 0.625

The standard error of the test can be computed as follows:

[tex]SE = \sqrt{p(1-p) ( \dfrac{1} {n_1}+ \dfrac{1}{n_2} )}[/tex]

[tex]SE = \sqrt{0.625(1-0.625) ( \dfrac{1} {1000}+ \dfrac{1}{1000} )}[/tex]

[tex]SE = \sqrt{0.625(0.375) ( 0.001+0.001 )}[/tex]

[tex]SE = \sqrt{0.234375 (0.002)}[/tex]

[tex]SE = \sqrt{4.6875 * 10^{-4}}[/tex]

[tex]SE = 0.02165[/tex]

The test statistics is :

[tex]z =\dfrac{p_1-p_2}{S.E}[/tex]

[tex]z =\dfrac{0.65-0.60}{0.02165}[/tex]

[tex]z =\dfrac{0.05}{0.02165}[/tex]

[tex]z =2.31[/tex]

At level of significance of 0.05  the critical value for the z test will  be in the region between - 1.96 and 1.96

Rejection region: To reject the null hypothesis if z < -1.96 or z > 1.96

Conclusion: Since the value of z is greater than 1.96, it lies in the region region. Therefore we reject the null hypothesis and we conclude that  the percentage of men and women favoring a higher legal drinking age is different.