







The rejection region 
20100501 

From Mong: In Tests of Hypothesis, what is the decision when the test statistic we compute from the sample information is exactly equal to the critical value? that is, we reject null hypothesis or do not reject it?
Thanks! Answered by Chris Fisher. 





Null hypothesis 
20070513 

From Dani: A poll of 1068 American voters indicated that 48% supported te Democratic candidate for presidency. At the 0.05 level of significance, test the claim that less than 50% of American voters preferred the Democratic candidate. Answered by Penny Nom. 





A hypothesis test 
20070409 

From Katrina: I have already tried to do this problem but im having a very had time with
it. Can you please help me.
Glamour Magazine sponsored a survey of 2500 prospective brides and
found that 60% of them spent less than $750 on their wedding gown.
Use a 0.01 significance level to test the claim that less than 62% of brides
spend less than $750 on their wedding gown. How are the results
affected if it is learned that the responses were obtained from magazine
readers who decided to respond to the survey through an Internet Web
site? Answered by Penny Nom. 





A standard deviation test 
20041109 

From Karen: How do you compare to see if a sample standard deviation is different than the population standard deviation? I know how to compare means, but not standard deviations. Answered by Penny Nom. 





The pvalue 
20040725 

From Kathy: Ms. Lisa Monnin is the budget director for the New Process Company. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample information.
At the .10 significance level, can she conclude that the mean daily expenses are greater for the sales staff than the audit staff? What is the pvalue?
Having problems finding the pvalue & unsure of the formula.
Kathy Answered by Penny Nom. 





Testing a hypothesis 
20020314 

From A student: A large distriutor of cosmetics has kept his outstanding accounts receivable to a mean age of 18 days over the past year. This average is considered a standard by which to measure the efficiency of the credit and collections department. Management wishes to check if receivables in the current month is over standard and will do this at a significance level of 0.50. A random sample of 100 accounts yields an average of 20 days with a standard deviation of 9 days. what should management conclude? Answered by Andrei Volodin. 

