Among 2450 randomly selected male car occupants over the age of​ 8, 76​% wear seatbelts. Among 2900 randomly selected female car occupants over the age of​ 8, ​74% wear seat belts. Use a 0.1 significance level to test the claim that both genders have the same rate of seat belt use. Does there appear to be a gender​ gap?

a. There appears to be a gender gap because there is not a significant difference in the proportions.
b. There does not appear to be a gender gap because there is a significant difference in the proportions.
c. There does not appear to be a gender gap because there is not a significant difference in the proportions.
d. There appears to be a gender gap because there is a significant difference in the proportions.

Respuesta :

Answer:

The correct option is D

Step-by-step explanation:

From the question we are told that

   The sample size for male car occupant is  [tex]n_1 = 2450[/tex]

   The number that wear seat belt is [tex]k_1 = \frac{76}{100} * 2450 = 1862[/tex]

   The sample size for female car occupant is [tex]n_2 = 2900[/tex]

   The number that wear a seat belt is   [tex]k_2 = \frac{74}{100} * 2900 = 2146[/tex]

Generally the population proportion is mathematically represented as

       [tex]p = \frac{x_1 + x_2 }{n_1 + n_2 }[/tex]

=>    [tex]p = \frac{1862 + 2146 }{2450 + 2900 }[/tex]

=>  [tex]p = 0.7492[/tex]

The sample proportion for male  car occupant is  

        [tex]\^ p_1 = \frac{k_1}{n_1}[/tex]

=>     [tex]\^ p_1 = \frac{1862}{2450}[/tex]

=>     [tex]\^ p_1 = 0.76[/tex]

The sample proportion for female car occupant is  

        [tex]\^ p_2 = \frac{k_2}{n_2}[/tex]

=>     [tex]\^ p_2 = \frac{2146}{2900}[/tex]

=>     [tex]\^ p_1 = 0.74[/tex]

The null hypothesis is  [tex]H_o : p_1 = p_2[/tex]

The alternative hypothesis is  [tex]H_a : p_1 \ne p_2[/tex]

Generally the standard error is mathematically represented as

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

=>    [tex]SE = \sqrt{\frac{0.7492 (1 -0.7492 )}{ 2450 + 2900} }[/tex]  

=>    [tex]SE = 0.005926[/tex]

Generally the test statistics is mathematically represented as

     [tex]z = \frac{\^ p_1 - \^ p_2}{SE}[/tex]    

=>   [tex]z = \frac{0.76 -0.74}{0.005926}[/tex]

=>   [tex]z = 3.37[/tex]

From the z table  the area under the normal curve to the right  corresponding to  3.37 is  

       [tex]P(Z > 3.37) = 0.00037584[/tex]

Generally the p-value is mathematically represented as

      [tex]p-value = 2 * P(Z > 3.37)= 2* 0.00037584 = 0.0007 5[/tex]

From the value obtained we see that  [tex]p-value < \alpha[/tex]  hence  

The decision rule is  

  Reject the null hypothesis

The conclusion is

 There appears to be a gender gap because there is a significant difference in the proportions