What does it mean that a result is statistically significant at the 5% level?

H_0

is true with probability 95%, given the dataCorrect answerYour answerThe result is large enough to matter in practiceCorrect answerYour answer5% of the sample units were measured wronglyCorrect answerYour answerUnder

H_0

, such a result has under a 5% chanceCorrect answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer D

Correct answer: D

Significance compares the result with what chance alone would give if $H_0$ held.
At 5%, a result is significant when chance would produce one so extreme less than 5% of the time.

Worth noting

A significance level does not give the probability that $H_0$ is true.

Concept: Statistical significance
Typical timeTypical: 90 s
Your timeYours: —

The rule this testsParameters, statistics and the central limit theorem

Practise this chapter →

Ten questions from Sampling, Inference & the t-Test, at your own pace.

What does it mean that a result is statistically significant at the 5% level?

Explanation