Respuesta :
Answer:
d. There is not enough evidence to support the hypothesis that the proportion of Uniformian voters has decreased.
Step-by-step explanation:
This is a hypothesis test for a proportion.
The claim is that there is a significant drop in allegiance to the Uniformian Party in Bowie County.
Then, the null and alternative hypothesis are:
[tex]H_0: \pi=0.62\\\\H_a:\pi<0.62[/tex]
The significance level is 0.05.
The sample has a size n=196.
The sample proportion is p=0.57.
The standard error of the proportion is:
[tex]\sigma_p=\sqrt{\dfrac{\pi(1-\pi)}{n}}=\sqrt{\dfrac{0.62*0.38}{196}}\\\\\\ \sigma_p=\sqrt{0.001202}=0.035[/tex]
Then, we can calculate the z-statistic as:
[tex]z=\dfrac{p-\pi+0.5/n}{\sigma_p}=\dfrac{0.57-0.62+0.5/196}{0.035}=\dfrac{-0.047}{0.035}=-1.369[/tex]
This test is a left-tailed test, so the P-value for this test is calculated as:
[tex]\text{P-value}=P(z<-1.369)=0.0855[/tex]
As the P-value (0.0855) is greater than the significance level (0.05), the effect is not significant.
The null hypothesis failed to be rejected.
There is not enough evidence to support the claim that there is a significant drop in allegiance to the Uniformian Party in Bowie County.
