Answer :
Sure, let's go through each part of this problem step-by-step, incorporating the information you provided.
### a) Hypothesis Test
#### Null and Alternative Hypotheses:
For the hypothesis test, we need to determine whether the proportion of students who believe that freedom of the press is secure is the same in 2016 and 2017.
- Null Hypothesis ([tex]\(H_0\)[/tex]): The proportion in 2016 is equal to the proportion in 2017.
[tex]$H_0: p_1 = p_2$[/tex]
- Alternative Hypothesis ([tex]\(H_a\)[/tex]): The proportion in 2016 is different from the proportion in 2017.
[tex]$H_a: p_1 \neq p_2$[/tex]
So, the correct option is:
D. [tex]\(H_0: p_1 = p_2\)[/tex], [tex]\(H_a: p_1 \neq p_2\)[/tex].
#### Test Statistic:
The test statistic for this hypothesis test is the z-score, which has been provided.
- Test Statistic:
[tex]$ z = -10.53 $[/tex]
#### p-value:
The p-value is used to determine the significance of our test statistic.
- p-value:
[tex]$ p\text{-value} = 0 $[/tex]
#### Decision:
We compare the p-value with the significance level ([tex]\(\alpha = 0.01\)[/tex]) to decide whether to reject the null hypothesis.
- Since the p-value (which is very close to zero) is less than [tex]\( \alpha = 0.01 \)[/tex], we reject the null hypothesis.
Conclusion:
There is sufficient evidence to support the claim that the 2016 proportion is different from the 2017 proportion.
Filling the part:
Since the p-value is less than the significance level of [tex]\( \alpha = 0.01 \)[/tex], reject the null hypothesis. There is sufficient evidence to support the claim that the 2016 proportion is different from the 2017 proportion.
### b) Confidence Interval
We are asked to construct a 98% confidence interval for the difference in proportions of college students who felt freedom of the press was secure in 2016 and 2017.
- The result from the Python code provides this:
- Confidence Interval: [tex]\((-0.133, -0.088)\)[/tex]
So, the 98% confidence interval is:
[tex]$ (-0.133, -0.088) $[/tex]
### How does the confidence interval support the hypothesis test conclusion?
The confidence interval [tex]\((-0.133, -0.088)\)[/tex] does not include 0, which means there is a significant difference in proportions. Since 0 is not within this interval, we reject the null hypothesis at the 1% significance level, supporting our hypothesis test conclusion that the 2016 proportion is different from the 2017 proportion.
### a) Hypothesis Test
#### Null and Alternative Hypotheses:
For the hypothesis test, we need to determine whether the proportion of students who believe that freedom of the press is secure is the same in 2016 and 2017.
- Null Hypothesis ([tex]\(H_0\)[/tex]): The proportion in 2016 is equal to the proportion in 2017.
[tex]$H_0: p_1 = p_2$[/tex]
- Alternative Hypothesis ([tex]\(H_a\)[/tex]): The proportion in 2016 is different from the proportion in 2017.
[tex]$H_a: p_1 \neq p_2$[/tex]
So, the correct option is:
D. [tex]\(H_0: p_1 = p_2\)[/tex], [tex]\(H_a: p_1 \neq p_2\)[/tex].
#### Test Statistic:
The test statistic for this hypothesis test is the z-score, which has been provided.
- Test Statistic:
[tex]$ z = -10.53 $[/tex]
#### p-value:
The p-value is used to determine the significance of our test statistic.
- p-value:
[tex]$ p\text{-value} = 0 $[/tex]
#### Decision:
We compare the p-value with the significance level ([tex]\(\alpha = 0.01\)[/tex]) to decide whether to reject the null hypothesis.
- Since the p-value (which is very close to zero) is less than [tex]\( \alpha = 0.01 \)[/tex], we reject the null hypothesis.
Conclusion:
There is sufficient evidence to support the claim that the 2016 proportion is different from the 2017 proportion.
Filling the part:
Since the p-value is less than the significance level of [tex]\( \alpha = 0.01 \)[/tex], reject the null hypothesis. There is sufficient evidence to support the claim that the 2016 proportion is different from the 2017 proportion.
### b) Confidence Interval
We are asked to construct a 98% confidence interval for the difference in proportions of college students who felt freedom of the press was secure in 2016 and 2017.
- The result from the Python code provides this:
- Confidence Interval: [tex]\((-0.133, -0.088)\)[/tex]
So, the 98% confidence interval is:
[tex]$ (-0.133, -0.088) $[/tex]
### How does the confidence interval support the hypothesis test conclusion?
The confidence interval [tex]\((-0.133, -0.088)\)[/tex] does not include 0, which means there is a significant difference in proportions. Since 0 is not within this interval, we reject the null hypothesis at the 1% significance level, supporting our hypothesis test conclusion that the 2016 proportion is different from the 2017 proportion.