What three items are needed in order to construct a confidence interval to estimate the mean of a ...

What three items are needed in order to construct a confidence interval to estimate the mean of a population?

Q. 2

Using the same sample data, the margin of error for an 80 confidence interval is __________ than the margin of error for a 90 confidence interval.
 Fill in the blank(s) with correct word

Q. 3

To obtain a 99.7 (virtually all-encompassing) confidence interval for the true population proportion, you would add and subtract about __________ standard deviations to/from the sample proportion.
 Fill in the blank(s) with correct word

Q. 4

In which of the following situations can a confidence interval provide useful information for making a decision?
 a. To assess whether or not at least 90 of a company's financial entries are correct.
  b. To estimate the percentage of married couples in which the wife is taller than the husband.
  c. To help determine whether or not someone has ESP (versus just being a lucky guesser).
  d. All of the above.

Q. 5

In which of the following situations can you construct a confidence interval for the population proportion with only what is given?
 a. The sample proportion and the margin of error.
  b. The sample proportion and the sample size.
  c. The number of individuals in the sample with the trait of interest, and the total sample size.
  d. All of the above.

Q. 6

Sampling methods and confidence intervals are routinely used for financial audits of large companies. Which of the following is an advantage of doing it this way, versus having a complete audit of all records?
 a. It is much cheaper.
  b. A sample can be done more carefully than a complete audit.
  c. A well-designed sampling audit may yield a more accurate estimate than a less carefully carried out complete audit or census.
  d. All of the above.