10.6 Matched or Paired Samples

A company has developed a training program for its entering employees because management has become concerned with the results of the six-month employee review. They hope that the training program can result in better six-month reviews. Each trainee constitutes a “pair”, the entering score the employee received when first entering the firm and the score given at the six-month review. The differenc…

What is the random variable?

What conclusion can you draw about the software patch?

State the null and alternative hypotheses.

What is the conclusion?

Ten individuals went on a low–fat diet for 12 weeks to lower their cholesterol. The data are recorded in the table. Do you think that their cholesterol levels were significantly lowered?

A local cancer support group believes that the estimate for new female breast cancer cases in the south is higher in Year 2 than in Year 1. The group compared the estimates of new female breast cancer cases by southern state in Year 1 and in Year 2. The results are in the table.

A politician asked their staff to determine whether the underemployment rate in the northeast decreased year over year. The results are in the table.

A new chocolate bar is taste-tested on consumers. Of interest is whether the proportion of children who like the new chocolate bar is greater than the proportion of adults who like it.

A football league reported that the mean number of touchdowns per game was five. A study is done to determine if the mean number of touchdowns has decreased.

According to a YWCA Rape Crisis Center newsletter, 75% of rape victims know their attackers. A study is done to verify this.

A recent drug survey showed an increase in use of drugs and alcohol among local high school students as compared to the national percent. Suppose that a survey of 100 local youths and 100 national youths is conducted to see if the proportion of drug and alcohol use is higher locally than nationally.

University of Michigan researchers reported in the Journal of the National Cancer Institute that quitting smoking is especially beneficial for those under age 49. In this American Cancer Society study, the risk (probability) of dying of lung cancer was about the same as for those who had never smoked.

A golf instructor is interested in determining if a new technique for improving players’ golf scores is effective. The instructor takes four (4) new students and records their 18-hole scores before learning the technique and then after having taken the class. The instructor conducts a hypothesis test. The data are as the table.

This is:

1. a test of two independent means.
2. a test of two proportions.
3. a…