The mayor of a town has proposed a plan for the construction of an adjoining bridge. A political study took a sample of 1700 voters in the town and found that 66% of the residents favored construction. Using the data, a political strategist wants to test the claim that the percentage of residents who favor construction is more than 63%.
A) Testing at the 0.02 level, is there enough evidence to support the strategist's claim?

Respuesta :

Answer:

[tex]z=\frac{0.66 -0.63}{\sqrt{\frac{0.63(1-0.63)}{1700}}}=2.562[/tex]  

[tex]p_v =P(z>2.562)=0.0052[/tex]  

So the p value obtained was a very low value and using the significance level given [tex]\alpha=0.02[/tex] we have [tex]p_v<\alpha[/tex] so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that at 2% of significance the proportion of voters that favored construction is higher than 0.63 or 63%.

Step-by-step explanation:

Data given and notation

n=1700 represent the random sample taken

[tex]\hat p=0.66[/tex] estimated proportion of voters that favored construction

[tex]p_o=0.63[/tex] is the value that we want to test

[tex]\alpha=0.02[/tex] represent the significance level

Confidence=98% or 0.98

z would represent the statistic (variable of interest)

[tex]p_v[/tex] represent the p value (variable of interest)  

Concepts and formulas to use  

We need to conduct a hypothesis in order to test the claim that percentage of residents who favor construction is more than 63%.:  

Null hypothesis:[tex]p \leq 0.63[/tex]  

Alternative hypothesis:[tex]p > 0.63[/tex]  

When we conduct a proportion test we need to use the z statisitc, and the is given by:  

[tex]z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}[/tex] (1)  

The One-Sample Proportion Test is used to assess whether a population proportion [tex]\hat p[/tex] is significantly different from a hypothesized value [tex]p_o[/tex].

Calculate the statistic  

Since we have all the info requires we can replace in formula (1) like this:  

[tex]z=\frac{0.66 -0.63}{\sqrt{\frac{0.63(1-0.63)}{1700}}}=2.562[/tex]  

Statistical decision  

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.  

The significance level provided [tex]\alpha=0.02[/tex]. The next step would be calculate the p value for this test.  

Since is a right tailed test the p value would be:  

[tex]p_v =P(z>2.562)=0.0052[/tex]  

So the p value obtained was a very low value and using the significance level given [tex]\alpha=0.02[/tex] we have [tex]p_v<\alpha[/tex] so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that at 2% of significance the proportion of voters that favored construction is higher than 0.63 or 63%.

ACCESS MORE
ACCESS MORE
ACCESS MORE
ACCESS MORE