proportion of women with a pattern of \"nonpeak sleep\" is higher in the breast cancer pOpulation? To justify your answer, use an apprOpriate test of hypothesis at level a = 0.10. Problem 14.5. The purpose of the study [19] was to investigate whether exposure to light at night may increase the risk of breast cancer, by sup- pressing the normal nocturnal production of melatonin by the pineal gland, which in turn could increase the release of estrogen by the ovaries. The case patients were 813 women aged 20 to 74 years with a new diagnostic of breast cancer. The control subjects were 792 women aged 20 to 74 years with no history of breast cancer. The subject was considered to experience a pat tern of \"nonpeak sleep\" if she reported the following (at least once a week): 1) turning off the lights to go to sleep after 2:00 a.m., 2) rising for the day before 1:00 a.m., or 3) not going to bed at all. 104 of the case patients and 91 of the control subjects reported having experienced a pattern of \"nonpeak sleep\" in the 10 years before the study. Can we argue that the