Statistical Inference

Statistical inference is the process of drawing conclusions about a population based on data from a sample.

A point estimate is a single value computed from a sample used to estimate a population parameter, such as x̄ for μ.

A confidence interval is a range of plausible values for a population parameter, computed so that it captures the parameter with a stated confidence level.

It is point estimate ± margin of error, where the margin of error = critical value × standard error.

If we repeated the sampling many times, about 95% of the resulting intervals would contain the true parameter.

A higher confidence level uses a larger critical value, producing a wider interval.