Question 780109
A medical researcher says that at least 23% of adults are smokers. 

Ho: p <= 0.23
Ha: p > 0.23 (claim)
p-hat = 0.224
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In a random sample 250 adults, 22.4% say they are smokers.
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What is the standardized test static? 
z(0.224) = (0.224-0.23)/sqrt(0.23*0.77/250) = -0.2254
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At alpha=0.03, what is critical value of zo?
invNorm(0.03) = -1.8808
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At alpha=0.03, is there enough evidence to reject the researcher's claim?
Ans: No
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What would be the correct conclusion of the test? Fail to reject or reject?
Fail to reject.
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Cheers,
Stan H.
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