Question 205362This question is from textbook Applied Statistics in Business and Economics, by Doane Seward
: A consumer agency tested 290 hams, finding that 64 were underweight. (a) Construct a 95 percent confidence interval for the true percent of underweight hams. (b) If the goal is to reduce the incidencw of underweight hams to 25 percent or less, does this sample show that the goal is being acheived? (c) Explain how this confidence interval is equivalent to a two-tailed test at a=.05.
This question is from textbook Applied Statistics in Business and Economics, by Doane Seward
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A consumer agency tested 290 hams, finding that 64 were underweight.
(a) Construct a 95 percent confidence interval for the true percent of underweight hams.
sample proportion: 64/290 = 0.22..
Margin of error: E = 1.96*sqrt[0.22*0.78/290] = 0.047
95% CI: 0.22-0.047 < p < 0.22+0.047
95% CI: (0.173 , 0.268)
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(b) If the goal is to reduce the incidence of underweight hams to 25 percent or less, does this sample show that the goal is being achieved?
0.25 in the 95% confidence interval so we would not reject an Ho
which stated p<=0.25
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Show how this confidence interval is equivalent to a two-tailed test at a=.05.
The left and right limits of the confidence interval correspond to the
critical values for a two-tailed test with alpha = 5%.
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Cheers,
Stan H.
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