Rounded Confidence Interval Calculation Results:

• Mean Difference ($\bar{d}$): $4.700$
• Standard Deviation of Differences ($s_d$): $5.458$
• t-Critical Value for 90% Confidence Level: $1.833$
• Margin of Error: $3.164$
• 90% Confidence Interval: $(1.536, 7.864)$

Interpretation:

We are 90% confident that the true mean difference in textbook prices between Site A and Site B is between $1.536$ and $7.864$.

Any other questions, or anything else you'd like to explore?

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Here are some additional related questions:

1. How does rounding impact the precision of confidence intervals?
2. What happens to the confidence interval if the standard deviation increases?
3. Why is it important to report confidence intervals in research studies?
4. How can confidence intervals be used to compare more than two groups?
5. What is the difference between a one-sided and a two-sided confidence interval?
6. How would this confidence interval change with a larger sample size?
7. What factors can influence the width of a confidence interval?
8. How can confidence intervals help in hypothesis testing?

Tip: When reporting results, consistently round all related values to the same number of decimal places for clarity.