Question

What are the key things we need to accurately calculate a required sample size?

1) Population size, Confidence level, Margin of error
2) Sample size, Confidence level, Margin of error
3) Population size, Sample size, Margin of error
4) Population size, Sample size, Confidence level

Answer 1

1) Population size, Confidence level, Margin of error

To calculate a required sample size, one needs the population size, confidence level, and margin of error. Knowing the distribution of the population, ensuring a sufficiently large sample, and a population size much larger than the sample, are also important considerations.

Step-by-step explanation:

The key things needed to accurately calculate a required sample size are:

1. Population size, which is the total number of individuals or observations that belong to the group that the researcher is interested in studying.
2. Confidence level, which reflects how certain we can be that if we were to take multiple samples, the true population parameter would lie within the confidence interval. Common confidence levels are 90%, 95%, and 99%.
3. Margin of error, which indicates how close the estimate from the sample is to the population parameter. It is often expressed as a percentage and is influenced by factors such as variability in the population and the size of the sample.

Regarding the choices provided, the correct elements required to calculate sample size are option 1) Population size, Confidence level, Margin of error.

Some additional considerations when calculating sample size include knowing the distribution of the population, ensuring the sample is large enough (typically at least 30 observations or following a normal distribution), and that the population is adequately larger than the sample to avoid over-sampling.