3. A UCLA researcher claims that the life span of mice can be extended by as much as 25% when the calories in their diet are reduced by approximately 40% from the time they are weaned. The restricted diet is enriched to normal levels by vitamins and protein. Assuming that it is known from previous studies that σ = 5.8 months, how many mice should be included in our sample if we wish to be 99% confident that the life span of the sample will be within 2 months of the population mean for all mice subjected to this reduced diet? 4. An electrical firm manufactures light bulbs that have a length life with normal distribution, and a standard devi-

a) If the prevalence rate is 50%, the sensitivity is 85%, and the specificity is 90%, what will the PPV value be? b) What are possible slider values that will produce a PPV value of 1? c) What are possible slider valuse that will produce an NPV value of 1? d) If sensitivity and specificity remain constant while prevalence decreases, what effect does that have on the PPV? e) If prevalence and specificity remain constant while sensitivity increases, what effect does that have on the NPV?

14.11 To test compliance with authority, a classical experiment in social psychology requires subjects to administer increasingly painful electric shocks to seemingly helpless victims who agonize in an adjacent room.* Each subject earns a score between 0 and 30, depending on the point at which the subject refuses to comply with authority—an investigator, dressed in a white lab coat, who orders the administration of increasingly intense shocks. A score of 0 signifies the subject’s unwillingness to comply at the very outset, and a score of 30 signifies the subject’s willingness to comply completely with the experimenter’s orders.    Ignore the very real ethical issues raised by this type of experiment, and assume that you want to study the effect of a “committee atmosphere” on compliance with authority. In one condition, shocks are administered only after an affirmative decision by the committee, consisting of one real subject and two associates of the investigator, who act as subjects…