You Plan to Select a Simple Random Sample to Estimate

Multiple Choice

You plan to select a simple random sample to estimate a population average.You initially decide to construct a confidence interval that is no wider than plus or minus 5.0.Making a rough estimate of the variability in the population, you determine the required sample size.Choose which of the four situations described below would require you to increase your sample size.Assume any factor not mentioned remains constant.There may be more than one answer.

A) You want a higher level of confidence.
B) You want a tighter interval.
C) You decide that you can live with a lower confidence level.There is more variability in the population of values than you had first estimated.
D) You want a tighter interval.You require a higher level of confidence.There is less variability in the population of values than you had first estimated.
E) Both a and b are correct.