Question

explain how sample size, confidence level, and confidence interval size are related? What is the role of the project's budget in determining sample size?

Answer 1

Let us first define sample size, confidence level and confidence interval.

Sample size: It is determination of the number of elements from a given population which accurately replicates the behaviour of the population.

Confidence interval: It gives an estimated range of values which is likely to include an unknown population parameter

Confidence level: It is the probability that the interval estimate will contain the parameter

For a given confidence level, increasing the sample size decreses the width of the confidence interval (inverse square root relationship between confidence intervals and sample size)

Project's budget is important as it the is constraint to having a large sample size which replicates better behaviour of the population and decreases margin of error