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According to the Brookings Institution, 50% of eligible 18- to 29-year-old voters voted in the 2016 election. Suppose we were interested in whether the proportion of voters in this age group who voted in the 2018 election was higher. Describe the two types of errors one might make in conducting this hypothesis test.

User Tompee
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Answer:

Explanation:

In a hypothesis test, there are two types of errors that can occur: Type I error and Type II error.

Type I Error (False Positive):

Definition: This error occurs when the null hypothesis is true, but we incorrectly reject it.

In the context of the voting example, a Type I error would mean concluding that the proportion of 18- to 29-year-old voters who voted in the 2018 election was higher when, in fact, it was not.

Probability of Type I Error: Denoted by the symbol α, it represents the significance level chosen for the test. Common values are 0.05 or 0.01. Lowering the significance level reduces the chance of Type I error but increases the chance of Type II error.

Type II Error (False Negative):

Definition: This error occurs when the null hypothesis is false, but we fail to reject it.

In the context of the voting example, a Type II error would mean failing to detect that the proportion of 18- to 29-year-old voters who voted in the 2018 election was higher when, in fact, it was.

Probability of Type II Error: Denoted by the symbol β, it depends on factors such as sample size, effect size, and the chosen significance level (α). Power of the test (1−β) is a related concept and represents the probability of correctly rejecting a false null hypothesis.

User Shamika
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