Question

ndomly give Drug A to half of the libjects in each group, and Drug B to the other half. (E) subjectively divide the 60 subjects into 30 pairs according to their characteristics (such as degree of hypertension), making the subjects within a pair as similar as possible, and then flip a coin to decide which subject in each pair will receive Drug A or Drug B. 31. You walk to the bus stop not knowing when the next bus will come. The time you have to wait follows a uniform distribution from 0 to 7 minutes. What proportion of the time will you have to wait less than one minute or more than five minutes for the bus to come? (A) 0.5714 (B) 0.1892 (C) 0.4286 (D) 0.2857 (E) 0.3640 x<5 = 1-xct 14

Answer 1

Let X be the random variable which denotes the time you to wait for next bus (in minutes)

X ~ Unif(0,7)

f(x) = 1/7, 0 < x < 7

The required proportion of time = P(X < 1) + P(X > 5)

= (1 - 0)/(7 - 0) + (7 - 5)/(7 - 0)

= 3/7 = 0.4286