Machine-translated by Google. Questions are authored in English.
Top

Discussion

In statistical hypothesis of equality of means such as H0 : μ = 10, if α = 5% :

  • A.95% of the time we will make an incorrect inference
  • B.5% of the time we will say that there is no real difference when there is no difference
  • C.5% of the time we will say that there is a real difference when there is no difference
  • D.95% of the time the null hypothesis will be correct

Answer: C

With α = 5%, 5% of the time we will say that there is a real difference when there is no difference.

α is the probability of a Type I error: rejecting H0 when it is true. Here H0 says the mean is 10, so rejecting it amounts to declaring a real difference from 10. If H0 is in fact true and the test is repeated many times, it will wrongly declare a difference in about 5% of cases.

Saying there is no real difference when there is none is the correct decision, which happens 95% of the time, not 5%. An incorrect inference 95% of the time reverses the figures, and α says nothing about how often the null hypothesis is true, which rules out the last option.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.