Question 126774
A coin was flipped 60 times and came up heads 38 times. A. At the .10 level of signifiance, is the coin biased toward heads? Show your decision rule and calculations.
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Ho: p = 1/2
Ha: p = 1/2
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x = 38 ; n= 60; so p-hat = 38/60 = 0.63333
alpha = 10% so the critical values for this 
two-tail test are z =-1.645,& +1.645
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Test statistic:
z(0.6333)= (0.6333-0.5)/sqrt[(0.6333)(0.3667)/60] = 0.1333/0.0622 =2.1426
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Since the test statistic is greater than the critical value, reject Ho
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B. Calculate a p-value and interpret it.
p-value = 0.01607
Interpretation: Only 1.6% of test results could have given stronger
evidence that the coin is biased away from p=1/2.
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Cheers,
Stan H.