Suppose that only 35% of all drivers come to a complete stop at an intersection having flashing red lights in all directions when no other cars are...

Suppose that only 35% of all drivers come to a complete stop at an

intersection having flashing red lights in all directions when no other cars are

visible. Suppose 12 drivers coming to such an intersection under these

conditions are randomly selected.

a What is the probability that exactly 7 drivers in the sample will come to

a complete stop?

b What is the probability that fewer than 5 drivers in the sample will come

to a complete stop?

c What is the probability that between 4 and 7 (inclusive) drivers in the

sample will come to a complete stop?

Let X be a continuous random variable with cumulative distribution function

F(x)=

a WhatisP(2≤X≤3.5)?

b WhatisP(X=3)?

c Find the probability density function of X.

Assume that the diameter at breast height (in.) of trees of a certain type is

normally distributed with a mean of 8.8 in. and a standard deviation of 2.8 in.

a What is the probability that a randomly selected tree will be at least 12

in. in diameter?

b What is the probability that the diameter of a randomly selected tree

will be between 5 and 10 in.?

c 15% of all tree diameters for this type of tree exceed what value?

d If four trees are independently selected, what is the probability that at

least one has a diameter exceeding 12 in.?