http://www.lock5stat.com/StatKey/index.html Activity 1: Create a randomization d
ID: 3051138 • Letter: H
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http://www.lock5stat.com/StatKey/index.html
Activity 1: Create a randomization distribution This activity is meant to have you participate in the creation of a randomization distribution to understand that it shows a distribution of sample statistics that were created assuming the null hypothesis is true. Every year in Punxsutawney, Pennsylvania a famous groundhog, Phil, makes a prediction about the end of winter. If he comes out of his burrow and sees his shadow he predicts six more weeks of winter. If he does not see his shadow, his prediction is an early spring. In the ten years from 2007 to 2016 he has been correct seven times: Prediction accuracy Correct Correct Correct Year Prediction | February Temperature 2016 End of winter Above Normal 2015 More winter Below normal 2014 More winter Below normal 2013 End of winter Above normal 2012 | More winter Below normal 2011 End of winter Below normal 2010 More winter Below normal 2009 More winter Above normal 2008 More winter Above normal 2007 | End of winter Above normal Are his predictions better than a random 50-50 chance? Correct Correct Incorrect Correct Incorrect Incorrect Correct 1. What are the correct null and alternative hypotheses? Hint - what is p if his predictions are random? Ha: Ho:Explanation / Answer
Answer to questioN# 1)
The hypothesis is as follows:
Null hypothesis: proportion of correct prediction is 50% or 0.50
Alternate hypothesis: proportion of correct prediction is Not equal to 50% or 0.50
[These hypothesis are framed on the basis of random assignment]
.
Answer to questioN# 2)
As per the example , we got 7 out of 10 trials where the prediction was correct
hence sample proportion p^ = 7/10 = 0.7000
.
Answer to question# 3)
If we flip the coin , that has 50% of chance of getting head, in order to get a radomzied distribution for it the sample size must be same as that of Phil
So since Phil had made 10 predictions , we need to flip the coin 10 times
Thus the sample size must be 10
.
Answer to question# 4)
The output of all the 10 tosses are as follows:
Head
Head
Tail
Head
Tail
Tail
Head
head
head
Tail
So the chances of getting head = 6/10 = 0.6000
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