Estimates

It isn't easy to measure a parameter such as the mean height or the mean weight of a population. So, we draw samples from the population and calculate …

Collecting samples or responses from an entire population takes significant time and effort, so a researcher collects responses from only a sample of that …

An unbiased point estimate is often insufficient to predict a population estimate, such as population mean or population proportion. In this scenario, a …

A confidence interval is a better estimate of the population than a point estimate, as it uses a range of values from a sample instead of a single value. …

A critical value is a definite value obtained from a particular probability distribution at a predecided confidence level (or a predecided significance …

The margin of error is also called the maximum error of an estimate. The margin of error is the maximum possible or expected difference between the …

Knowledge of the sample size is the first requirement to conduct random sampling or an experiment. The sample size is the total number of units, …

To construct a confidence interval for a single unknown population mean μ, where the population standard deviation is known, we need sample mean as …

A point estimate of the population mean is obtained from a single sample. Such a point estimate does not represent a population well because it needs to …

The confidence coefficient is also known as the confidence level or degree of confidence. It is the percent expression for the probability, 1-α, that …

In practice, we rarely know the population standard deviation. In the past, when the sample size was large, this did not present a problem to …