Question 61950
1. The sample mean is 12 for a sample of 36. The population standard deviation is 3. Use the .02 significance level.
Ho:u <= 10 
Ha:u >10 
Population DATA: mu=10,sigma=3
Sample DATA; n=36, s= 3/sqrt(36)=1/2, x-bar=12
Critical value for one-tail test with alph=0.02 is 2.05
Test statistic: z(12)=[12-10]/(1/2)=4
Conclusion:
Since the test statistic is > 2.05 we reject the null hypothesis.
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2. A sample of 64 observations is selected from a normal population. The sample mean is 215, and the sample standard deviation is 15. Conduct the following test of hypothesis using the .03 significance level. 
Ho: u >= 220 
Ho: u < 220 
Population DATA: u=220 
Sample DATA: n=64, s=15
Critical Value for alpha = 0.03 = -1.88
Test Statistic: t=-2.67
Conclusion:
Since the test statistic is to the left of the critical value
reject the null hypothesis.
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cheers,
Stan H.