Questions from Business Statistics

Q: a. What is a stratified random sample? b.

a. What is a stratified random sample? b. What are the benefits of stratification? c. When is stratification most likely to be helpful?

Q: a. What is a systematic sample? b. What

a. What is a systematic sample? b. What are the main problems with systematic samples? c. Why is there no reliable standard error available for use with a sample average computed from a systematic sam...

Q: a. What is a representative sample? b. What

a. What is a representative sample? b. What is a biased sample? c. How can a representative sample be chosen?

Q: a. What is a random sample? b. Why

a. What is a random sample? b. Why is a random sample approximately representative? c. What is the difference between a random sample selected with and one selected without replacement? d. What is a t...

Q: a. What is a pilot study? b. What

a. What is a pilot study? b. What can go wrong if you do not do a pilot study?

Q: a. What is an estimator? b. What is

a. What is an estimator? b. What is an estimate? c. A sample standard deviation is found to be 13.8. Is this number an estimator or an estimate of the population standard deviation? d. What is the err...

Q: a. What is the central limit theorem? b.

a. What is the central limit theorem? b. Does the central limit theorem specify that individual cases follow a normal distribution? c. How do you interpret the idea that the average has a normal distr...

Q: Test to see if the population mean age for training level A

Test to see if the population mean age for training level A differs from that for levels B and C combined.

Q: a. Why must a one-sided confidence interval always include

a. Why must a one-sided confidence interval always include the sample average? b. Must a one-sided confidence interval always include the population mean?

Q: a. What additional criterion must be satisfied for a one sided

a. What additional criterion must be satisfied for a one sided confidence interval to be valid (in addition to the two assumptions needed for a two-sided confidence interval)? b. If in doubt, should y...