Question

16) The table below shows the soft drinks groups. preferences of people in three age cola root beer lemon-lime bet ween 21 and 40 35 20 over 40 years of age 20 30 30 35 If one of the 255 subjects is randomly selected, find the probability that age given that they do not drink root beer the person is over 40 years of A) 0.353 B) 0.306 C) 0.4 D) None of the above is correct 17) You are dealt two cards successively (without replacement) from a shuffled deck of 52 playing cards. Find the probability that both cards are black. A) 0.490 B) 0.255 C) 0.245 D)0.0004 18) The age distribution of students at a community college is given below Under 21 21-25 26-30 31-35 411 411 202 58 1102 19)A student from the community college is selected at random Find the conditional probability that the student is at most 35 given that he or she is at least 26 A) 0.898 B) 0.929 C 0.207 D) 0.236

Answer 1

P(person is over 40 year /do not drink root beer) = p(person is over 40 years Intersection do not drink root beer)/p(do not drink root beer) = 30/255/(25 + 20 + 30)/255 = 30 /75 = 0.4 2) No. of black cards = 26 Total no. Of cards = 52 p(1st card is black) = 26/52 without replacement - no. Of black cards = 25 Total no of cards = 51 p(2^nd card is black) = 25/51 p(Both cards are black) = 26/52 times 25/51 = 0.245 3) p(student is at most 35/student is at least 26) = p(student is at most 35/student is at least 26)/p(student is at least 26) = (202 + 58)/1102/(202 + 58 + 20)/1102 = 260/280 = 0.929