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Nationwide Insurance would like to perform a chi-square test to investigate whether a difference exists in the proportion of male and female teenagers who text while they drive. A random sample of 80 male teenagers found that 50 indicated they texted while driving. A random sample of 120 female teenagers found that 65 indicated they texted while driving. The degrees of freedom for the chi-square critical value is ________.

User Lazy Ninja
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Answer:

1

Explanation:

There are 2 categories male and female and 1 attribute those who text during driving so the number of cells is 2*1= 2

And degrees of freedom is found by subtracting 1 from k= k-1= 2-1= 1 where k is the number of the categories

The degrees of freedom for this chi square test of proportions is 1

The critical value for ∝= 0.05 is .χ²≥ χ²(0.05,1)= 3.84

The critical value for ∝= 0.01 is .χ²≥ χ²(0.05,1)= 2.71