Answer: 3.6
Step-by-step explanation:
The test statistic for proportion is given by :-
[tex]z=\dfrac{\hat{p}-p}{\sqrt{\dfrac{p(1-p)}{n}}}[/tex], where p is the population proportion , [tex]\hat{p}[/tex] is the sample proportion and n is the sample size.
Let p be the population proportion of homes are not properly insulated.
As per given , we have
p= 0.25
Sample size : n= 300
In the sample, it was found that 102 homes were not properly insulated.
Then , [tex]\hat{p}=\dfrac{102}{300}=0.34[/tex]
The test statistic for proportion is given by :-
[tex]z=\dfrac{0.34-0.25}{\sqrt{\dfrac{0.25(1-0.25)}{300}}}\\\\=\dfrac{0.09}{\sqrt{0.000625}}\\\\=\dfrac{0.09}{0.025}=3.6[/tex]
Hence, the z-score for the sample proportion is: 3.6