A. Explain confidence interval. Why do we use confidence intervals? How can we be sure our true population parameter is in our confidence interval? B. Explain Margin of Error. Write out the formula and label the portion that is the MOE. C. What is something we should be cautious about with confidence intervals. D. Use your notes and explain what the P-value is. Your answer should be precisely worded. E. How do we know if a value is significantly high or significantly low? What determines the values significance?.