A publisher reports that 53%53% of their readers own a particular make of car. A marketing executive wants to test the claim that the percentage is actually different from the reported percentage. A random sample of 250250 found that 44%44% of the readers owned a particular make of car. Determine the P-value of the test statistic. Round your answer to four decimal places.

Respuesta :

Answer:

[tex]z=\frac{0.44 -0.53}{\sqrt{\frac{0.53(1-0.53)}{250}}}=-2.85[/tex]  

[tex]p_v =2*P(z<-2.85)=0.0044[/tex]  

Step-by-step explanation:

Data given and notation

n=250 represent the random sample taken

[tex]\hat p=0.44[/tex] estimated proportion of of the readers owned a particular make of car.

[tex]p_o=0.53[/tex] is the value that we want to test

[tex]\alpha=0.05[/tex] represent the significance level

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 the true porportion is equal to 0.53.:  

Null hypothesis:[tex]p=0.53[/tex]  

Alternative hypothesis:[tex]p \neq 0.53[/tex]  

When we conduct a proportion test we need to use the z statistic, 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{0.44 -0.53}{\sqrt{\frac{0.53(1-0.53)}{250}}}=-2.85[/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 next step would be calculate the p value for this test.  

Since is a bilateral test the p value would be:  

[tex]p_v =2*P(z<-2.85)=0.0044[/tex]