Question 836101: A researcher claims that the average score in the 2012 final exam of ST130 students is at least 69%. A random sample of 10 students is selected, and the scores in percentage are shown. 48 11 84 72 15 52 35 63 61 58 At = 0.025, is there enough evidence to reject the claim?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A researcher claims that the average score in the 2012 final exam of ST130 students is at least 69%. A random sample of 10 students is selected, and the scores in percentage are shown. 48 11 84 72 15 52 35 63 61 58 At alpha = 0.025, is there enough evidence to reject the claim?
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Ho: p >= 0.69 (claim)
Ha: p < 0.69
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p-hat = 49.9
std = 23.5
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z(49.9) = (49.9-69)/[23.5/sqrt(10)] = -2.57
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p-value = P(z < -2.57) = normalcdf(-100,-2.57) = 0.0051
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Conclusion: Since the p-value is less than 2.5%, reject Ho.
Reject the claim.
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Cheers,
Stan H.
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