12 approximately 1 in 14 men over the age of 50 has prostate cancer. the level of 'prostate specific antigen' (psa) is used as a preliminary screening test for prostate cancer 7% of men with prostate cancer do not have a high level of psa. these results are known as 'false negatives' 75% of those men with a high level of psa do not have cancer. these results are known as "false positives if a man over 50 has a normal level of psa, what are the chances that he has prostate cancer? a 7% b 25% c 5% d 07% 0.5%

Astudent is determining the influence of different types of food on the growth rate of spiders. she feeds one group of spiders two caterpillars twice a week. the other group received similarly-sized beetles twice a week. she records the amount of time required for individuals to reach sexual maturity. her hypothesis is that the spiders feeding on caterpillars will have a faster growth rate because caterpillars have a higher protein content compared to beetles. in this experiment, what is the dependent variable? spiders assigned to different feeding groups. time required to reach sexual maturity number of prey items fed twice a week. growth rates of each group.