Last answered:

21 Feb 2022

Posted on:

18 May 2021


Average height quiz question explanation

Following is the quiz question:

"You want to check if your height is above average, compared to your classmates. State the null and alternative hypotheses of this test."

Null hypothesis is the current state of affair. So why following is not true:

Null hypothesis is your height >= avg height

Question says, "your height is above average" so I thought that this should go with current state of affairs.

3 answers ( 0 marked as helpful)
Posted on:

26 May 2021


Hi Vipin,
thanks for reaching out! Designing hypothesis and statistics tests is tricky, especially in the beginning, so I'm glad you're asking this question.
The key in this test is that we'd like to see if we're above average or not. We're not certain of that fact.
The second thing to remember is that the Null Hypothesis, or Ho is what we'd like to reject. And H1 is the change/state we'd like to see.
Ideally, we'd like to be above average height, right? So, we'd like to see that fulfilled. So this is our H1.
And that means we'd like to reject the fact that we're lower or equal to the average height - so this is our Ho
I think you've gotten the idea of the test right, but to make things extra clear you can revisit the lecture on null vs alternative testing and also see the additional reading materials on the two examples from the lecture:
Statistics | 365 DataScience

365 Eli

Posted on:

14 Dec 2021


Thank you Elitsa, for this great answer.

Posted on:

21 Feb 2022


Exactly! Had his height being above average been the status quo, he wouldn't have thought of checking that in the first place.

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