Questions: Suppose a poll is taken that shows 222 out of 400 randomly selected users of a certain social media website feel that the site should do more to decrease hateful and abusive content on the site. Test the hypothesis that the majority (more than 50% ) of the site's users feel the site should do more to decrease hateful and abusive content on the site. Use a significance level of 0.05.
Determine the null and alternative hypotheses.
H0: p = 0.5
Ha: p > 0.5
(Type integers or decimals. Do not round.)
Transcript text: Suppose a poll is taken that shows 222 out of 400 randomly selected users of a certain social media website feel that the site should do more to decrease hateful and abusive content on the site. Test the hypothesis that the majority (more than $50 \%$ ) of the site's users feel the site should do more to decrease hateful and abusive content on the site. Use a significance level of 0.05.
Determine the null and alternative hypotheses.
\[
\begin{array}{l}
\mathrm{H}_{0}: \mathrm{p} \square \square \\
\mathrm{H}_{\mathrm{a}} \mathrm{P} \square \square
\end{array}
\]
(Type integers or decimals. Do not round.)
Solution
Solution Steps
Step 1: State the Hypotheses
We are testing the following hypotheses:
Null Hypothesis (\(H_0\)): \(p \leq 0.5\) (The proportion of users who feel the site should do more to decrease hateful and abusive content is less than or equal to 50%)
Alternative Hypothesis (\(H_a\)): \(p > 0.5\) (The proportion of users who feel the site should do more to decrease hateful and abusive content is greater than 50%)
Step 2: Calculate the Test Statistic
The test statistic is calculated using the formula:
\[
Z = \frac{\hat{p} - p_0}{\sqrt{\frac{p_0(1 - p_0)}{n}}}
\]
where:
\(\hat{p} = \frac{222}{400} = 0.555\)
\(p_0 = 0.5\)
\(n = 400\)
Substituting the values, we find:
\[
Z = \frac{0.555 - 0.5}{\sqrt{\frac{0.5(1 - 0.5)}{400}}} = 2.2
\]
Step 3: Determine the P-value
The P-value associated with the test statistic \(Z = 2.2\) is calculated to be:
\[
\text{P-value} = 0.0139
\]
Step 4: Compare with the Critical Value
For a significance level of \(\alpha = 0.05\) in a one-tailed test, the critical value of \(Z\) is:
\[
Z_{critical} = 1.6449
\]
Since \(Z = 2.2 > Z_{critical} = 1.6449\), we reject the null hypothesis.
Step 5: Conclusion
Given that the P-value \(0.0139 < 0.05\) and the test statistic \(Z = 2.2\) exceeds the critical value, we have sufficient evidence to reject the null hypothesis. Therefore, we conclude that the majority of users (more than 50%) feel that the site should do more to decrease hateful and abusive content.