Respuesta :
Answer:
a) [tex]z=\frac{0.239 -0.2}{\sqrt{\frac{0.2(1-0.2)}{180}}}=1.308[/tex]
b) [tex]p_v =P(z>1.308)=0.0954[/tex]
Step-by-step explanation:
Data given and notation
n=180 represent the random sample taken
X=43 represent the correct guesses
[tex]\hat p=\frac{43}{180}=0.239[/tex] estimated proportion correct guesses
[tex]p_o=0.2[/tex] is the value that we want to test
[tex]\alpha[/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 ture proportion is higher than 0.2 or no.:
Null hypothesis:[tex]p=0.2[/tex]
Alternative hypothesis:[tex]p > 0.2[/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].
Part a: Calculate the statistic
Since we have all the info requires we can replace in formula (1) like this:
[tex]z=\frac{0.239 -0.2}{\sqrt{\frac{0.2(1-0.2)}{180}}}=1.308[/tex]
Part b: 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 right tailed test the p value would be:
[tex]p_v =P(z>1.308)=0.0954[/tex]
