Radon is a gas produced when radium decays, and it can enter homes where it can be a health threat. among 180 homes in hyde park, 25 were found to have unsafe radon levels. among 230 homes in lagrange, 50 were found to have unsafe radon levels. use a .05 significance level to test that the two towns have different rates of unsafe radon levels. use our 4 step procedure.

We are given that Among 180 homes in Hyde Park, 25 were found to have unsafe radon levels. Among 230 homes in La Grange, 50 were found to have unsafe radon levels.

Claim : the two towns have different rates of unsafe radon levels.

Let and be the rates of unsafe radon levels of Hyde Park and LaGrange respectively .

Among 180 homes in Hyde Park, 25 were found to have unsafe radon levels

So,

Among 230 homes in La Grange, 50 were found to have unsafe radon levels.

So,

We will use Comparing Two Proportions

Formula of test statistic :

Substitute the values  

test statistic :

test statistic :  −2.053

Refer the z table for p value

p value = 0.0202

α= 0.05

Since p value < α

So, we reject the null hypothesis that the two towns have same rates of unsafe radon levels.

So, Claim is true.

341

step-by-step explanation:

all you have to do is 9x31 (which equals 279) and then 20x31 (which equals 620). then you have to subtract. 620-279=341.