Author Question: Sara is a frequent business traveler. For security purposes, 10 of all people boarding airplanes are ... (Read 82 times)

FButt · **on:** Jul 24, 2018

Sara is a frequent business traveler. For security purposes, 10 of all people boarding airplanes are randomly selected for additional screening just prior to boarding. Define the random variable X = number of flights Sara completes before being chosen for additional screening. For instance, if she is searched boarding her next flight, then X = 0 . What is the value of P(X = 2) = probability Sara completes two flights without screening and then is chosen for additional screening on the next one?
a. (0.1)2
b. (0.9)2
c. (0.1)2(0.9)
d. (0.9)2(0.1)

Question 2

Suppose that a 95 confidence interval for the proportion of teen drivers who were involved in a car accident is found to be (0.1425, 0.2875). Consider the following statement: If the sampling procedure were repeated many times, this would result in many different 95 confidence intervals. We would expect that 95 of the time, the true value of the population proportion would fall between 0.1425 and 0.2875.. Does this statement correctly interpret the meaning of the 95 confidence level?
a. Yes
b. No