The answer to part (c), the value of the test statistic, is:

$z \approx -2.718$

This value was calculated using the formula:

$z = \frac{\hat{p} - p_0}{SE}$

Where:

• $\hat{p} = 0.1345$ (sample proportion)
• $p_0 = 0.20$ (proportion under the null hypothesis)
• $SE \approx 0.0241$ (standard error)

The result is rounded to three decimal places as requested.

Would you like further details or have any more questions?

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Here are 5 questions related to this problem:

1. What would be the test statistic if the sample proportion was higher than 20%?
2. How does the standard error impact the test statistic?
3. What happens if you round the intermediate values differently?
4. How would a two-tailed test change the process?
5. What is the critical value for a one-tailed test at a 0.05 significance level?

Tip: For hypothesis testing, it's important to maintain consistency in rounding during intermediate steps to avoid discrepancies in the final test statistic.