The margin of error ($E$) for a given confidence level can be calculated using the formula:

$E = Z \times \text{Standard Error}$

Where:

• $Z$ is the Z-score corresponding to the desired confidence level.
• Standard Error is given as $0.4$.

For a 99% confidence level, the $Z$-score is approximately $2.576$.

Substitute the values:

$E = 2.576 \times 0.4 = 1.0304$

Margin of Error: $1.0304$

Would you like a detailed explanation of the process or any further assistance? Here are 5 related questions:

1. How is the $Z$-score determined for different confidence levels?
2. What is the relationship between the margin of error and sample size?
3. How does changing the confidence level affect the margin of error?
4. What role does standard error play in confidence intervals?
5. How would you calculate the margin of error for a confidence level of 95%?

Tip: Always ensure the sample size is sufficiently large to achieve reliable results in confidence interval calculations.