A cancer research group surveys a random sample of 400 women more than forty years old to test the hypothesis that 30% in this age group have regularly scheduled mammograms. Test if this hypothesis should be rejected at a 5% significance level if 140 women in the sample respond affirmatively?

A large clinical trial of the effect of diet on breast cancer assigned women at random to either a normal diet or a low-fat diet. To check that the random assignment did produce comparable groups, we can compare the two groups at the start of the study. Asked if there is a family history of breast cancer: 1276 of the 5964 women in the low-fat group and 1507 of the 7726 women in the control group said "Yes." If the random assignment worked well, there should not be a significant difference in the proportions with a family history of breast cancer. How significant is the observed difference? State: Is there evidence of a difference in the proportion of women with a family history of breast cancer between the treatment and control groups? Plan: Let pi be the proportion for the treatment group, and Pz the proportion for the control group. State the hypotheses for your test. Ha:Pi + P2 Solve: Give the value of the test statistic. Use the calculator. Select an answer ♥ Ho:pi = p2 What is the…

It is believed that 11% of all Americans are left-handed. A college needs to know how many left-handed desks to place in the big lecture halls being constructed on its campus. In a random sample of 120 students of its 12124 students, 15 were left-handed. Does this provide enough evidence to show that students at this college have a higher percentage of left-handers than the general American population? Use a 10% level of significance.

A company claims that at least 94% of equipment supplied to a manufacturer is within specifications. A test of a sample of 200 pieces of equipment showed that 27 of them were faulty. Test their claim at the 5% significance level?