Question

20. (4 points) If P(A) = 0.025, what are the odds in favor of event A to occur? A. 1:39 B. 1:38 C. 39:1 D. 0.025 21. (4 points) Suppose the probability that a student passes a math class is 0.6, and the probability that a student passes a psychology class is 0.8. Find the probability that a student passes a math class given that he/she has already passed the psychology class if the probability of passing both classes is 0.5. A. 0.625 B. 0.725 C. 0.525 D. 0.925 22. (4 points) Consider a uniform probability distribution for all values from 5 to 30. Find the probability of selecting a number that is between 7.5 and 17.5. Drawing required. A. 0.25 B. 0 C. 0.6 D. 0.4 23. (4 points) Given: n = 10 + = 72, and D2 = 551, Find its variance. A. 4 B. 3.955

Answer 1

20 PLA) -0.025. 25 1000 40 PLA) - m = no.of success Total (Success + feilwee) 40 therefore Odds in favour of ots euent = ho. of success ho of failure nam yot 39 Answer i 1:39 be

Pleases in math class) = 0.6 el passing psychology Class) = 0.8 Pl.eans in both class} =0.5 Pl students pass in math given already pass in psychology class) pleans in both clars) Pleas in psychologyclam) 0.5 08 0.625 Answer: 0:67 (22 D. d. f us given as - (according to uniform distribution) fln) = - b>a. bra 5

therefore probability of selecting a number between 5 and 7.5 is that us flry 25 175 Pl 7.5<.<17:) dra 25 7.5 17.5. 1. dhe 255 75 +75 - [x 20 25 7.5 117.5-7.5) - X03 0.4 25 Answer ® 0.4 23 n=10, E2572 Ex2=554 g

vlx) = EX2 (x2 therefore, メー EX b 72 = 702 ro 2 2. ex n. 554 10: (7.212 = 55.4 -51.89 < 3.56 Answer :- 3.56