Does Timmy really brush his teeth before bedtime? Remember when you were a kid and you were told to brush your teeth before
going to bed? How many of us pretended to brush our teeth thinking that no one
would notice? (It probably took more time to pretend than it would have been to
just brush our teeth in the first place.)
Here we have a null hypothesis, an alternative hypothesis, and the data (evidence).
Null the
Were Hypothesis
They rushed
His Teeth
Teled Not truth
e Tea
The Data
Dry Toothbrush
• What level of significance would you choose, 0.1 or 0.01? Explain.
. Would you reject or not reject the null hypothesis based on the data (a dry
toothbrush)? Explain.
Is there anything that could go wrong with your decision? Explain.
• If something could go wrong, what type of error would that be?