Exam 20: More About Tests

A university wants to increase its retention rate of 4% for graduating students from the previous year.After implementing several new programs during the last two years,the university reevaluated its retention rate using a random sample of 352 students and retained 18 students.Should the university continue its new programs? State the critical value required to perform an appropriate hypothesis test using α = 0.10.

A city claims that 75% of all low income housing is 1500 sq.ft.The tenants believe the proportion of housing this size is smaller than the claim,and hire an independent firm to test an appropriate hypothesis.What are the null and alternative hypotheses?

A researcher has tested the difference between the means of a treatment group and a placebo group.With a P-value of 0.034,he concludes there is a difference.

A weight loss centre provided a loss for 72% of its participants.The centre's leader decides to test a new weight loss strategy.Identify the Type I error in this context.

A skeptical paranormal researcher claims that the proportion of Americans that have seen a UFO,p,is less than 5%.Identify the Type II error in this context.

According to the 2004 Canadian Community Health Survey,23.1% of Canadians aged 18 or older were considered obese;that is,they had a body mass index (BMI)of 30 more higher.Suppose you believe that the percentage of obese Canadians has increased since 2004 and wish to test your belief.What are the null and alternative hypotheses?

A university wants to increase its retention rate of 4% for graduating students from the previous year.After implementing several new programs during the last two years,the university reevaluated its retention rate.Identify the Type I error in this context.

In April of 2011,the unemployment rate in Canada was reported to be 7.6%.Suppose that Statistics Canada claims that the current unemployment rate is lower than that of April 2011.Suppose you wish to conduct a test to determine if the current unemployment rate is lower than that of April 2011.Identify the Type II error in this context.

Farmers concerned with the affect of snowfall levels on their crops found that there wasn't evidence of a decrease in crop growth.They based this conclusion on a test using α = 0.10.Would they have made the same decision at α = 0.05 and α = 0.01?