Consider each of the following null hypotheses and decide whether in testing each of these hypotheses you would use a one-tail test or a two-tail test. In each case give brief reasons for your choice.

a. Students who are provided with a private tutor visiting their home are as likely to get good results as students who are not provided with this service.

b. High school students whose main outside interest is sports are as likely to do well at school as students whose main outside interest is computer games.

c. Plants that are watered three times a week grow just as rapidly as plants that are watered daily.

d. Patients having major surgical procedures fare equally well regardless of whether the surgery is performed by general practitioner surgeons or fully trained specialist surgeons.

e. Cyclists wearing white clothes are just as likely to be hit by a car at night as cyclists wearing clothes of other colors.

f. People with blood group A are just as likely as people with blood group B to contract rheumatoid arthritis. POLI967