SOLUTION: A researcher wants to determine whether or not the percentage in population A is less than the percentage in population B. A sample of 161 items from population A had a sample per

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Question 64374: A researcher wants to determine whether or not the percentage in population A is less than the percentage in population B. A sample of 161 items from population A had a sample percentage of 20% while a sample of 189 items from population B had a sample percentage of 25%. If a significance level of .05 is used, which of the following statements is correct?
1. left-tailed test with Z = -1.96
2. left-tailed test with Z = -1.65
3. left-tailed test with Z = +1.65
4. right-tailed test with Z = +1.65
5. left-tailed test with Z = -2.33
I figured t-score=1.113, degrees of freedom=348, its a two-tailed test=.2665, from here I am lost. can someone help me please....

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A researcher wants to determine whether or not the percentage in population A is less than the percentage in population B. A sample of 161 items from population A had a sample percentage of 20% while a sample of 189 items from population B had a sample percentage of 25%. If a significance level of .05 is used, which of the following statements is correct?
1. left-tailed test with Z = -1.96
2. left-tailed test with Z = -1.65
3. left-tailed test with Z = +1.65
4. right-tailed test with Z = +1.65
5. left-tailed test with Z = -2.33
I figured t-score=1.113, degrees of freedom=348, its a two-tailed test=.2665, from here I am lost.
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Since the researcher is testing "less than" the test is a left-tail test.
Since a significance level of 0.05 is stated you want z=-1.65
ANSWER is # 2
Cheers,
Stan H.