Question

In a survey, 45% of the interviewees are of age below 30, 30% are between 30 and 50, and 25% are above 50. 90% of the interviewees aged below 30, 60% of the interviewees aged between 30 and 50, and 70% of the interviewees aged above 50 can swim.

(a) If a randomly selected interviewee can swim, find the probability that his/her age is between 30 and 50.

(b) If a randomly selected interviewee cannot swim, find the probability that his/her age is below 30.

(Give your answers correct to 3 significant figures if necessary.)

Answer 1

0.90 Below 8.45 can swim o.10 can't swim between can swim 50 - 50 0.30 I can't swim 0-70 above 0.25 can swim can't swim. 0-30 @ Por (age between 30-50 I can swim) 0.30 x 0.60 - = 0.2368 0.30X0'60 + 0.45x0.90 +0-25 X0.70 10.237 $ 40.90 +0,25 *0.70* 0 Poslej ® Po (Age below so I cannot swim) 0.1807 0.45*0.10 - 0-4 S X0-10 +0.30 x 0-40 +0:25 *0*30.- : -10-1811