# SOLUTION: sorry if am adding more questions but please i need your help. The next question is a. A study considered risk factors for HIV infection among intravenous drug users. It found t

Algebra ->  Algebra  -> Probability-and-statistics -> SOLUTION: sorry if am adding more questions but please i need your help. The next question is a. A study considered risk factors for HIV infection among intravenous drug users. It found t      Log On

 Ad: Algebra Solved!™: algebra software solves algebra homework problems with step-by-step help! Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations!

 Algebra: Probability and statistics Solvers Lessons Answers archive Quiz In Depth

 Question 483266: sorry if am adding more questions but please i need your help. The next question is a. A study considered risk factors for HIV infection among intravenous drug users. It found that 40% of users who had 100 injections per month (light users) and 55% of users who had >100 injections per month (heavy users) were HIV positive. i. What is the probability that exactly 3 out of 5 light users are HIV positive? ii. What is the probability that at least 3 light users are HIV positive? Answer by stanbon(57967)   (Show Source): You can put this solution on YOUR website!a. A study considered risk factors for HIV infection among intravenous drug users. -------------------------- It found that 40% of users who had 100 injections per month (light users) and -------------------------- 55% of users who had >100 injections per month (heavy users) were HIV positive. ------------------------ i. What is the probability that exactly 3 out of 5 light users are HIV positive? Binomial Problem with n = 5 and p = 0.40 P(x = 3) = 5C3(0.4)^3*(0.6)^2 = 0.2304 ---------- ii. What is the probability that at least 3 light users are HIV positive? P(3<= x <=5) = 1 - binomcdf(5,0.4,2) = 0.3174 ====================== Cheers, Stan H. =========