Question 135217
A coin was flipped 60 times and came up heads 38 times.
p-hat = 38/60 = 19/30
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(a) at the .10 level of significance, is the coin biased toward heads?  Show your decision rule and calculations.
Ho: p= 1/2
Ha: p> 1/2
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Critical value of one-tail z-test with alpha = 5%: z = 1.645
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Test statistic: z(19/30) = ((19/30)-(1/2))/sqrt[(0.5*0.5)/60] = 0.1333/0.0645
= 2.0651
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Conclusion: Since test stat lies in the rejection interval, Reject Ho.
The test provides statistical evidence the coin is biased toward heads.
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(b) Calculate a p-value and interpret it.
p-value = P(2.0651 < z < 10) = 0.0191
That means there is only a 1.91% chance the statistical results could
have provided stronger evidence for rejecting Ho.
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Cheers,
Stan H.
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