6.A student must pass through 9 sets of traffic lights on his way to university each day. Suppose that each of the lights is red 30% of the time, yellow 10% of the time, and green 60% of the time. Suppose it is known that the traffic lights function independently. What is the probability that the student encounters at least 2 red lights on his way to university one day?

Select one:

a. 0.8040

b. 0.3222

c. 0.2668

d. 0.2428

e. 0.1960

7.Event A has a probability of 0.3 of occurring. Event B has a probability of 0.5 of occurring. If A and B are Mutually exclusive, then the probability P (A U B) is

Select one:

a. 0.02

b. 0.0

c. 0.15

d. 0.65

e. 0.8

8.A hotel chain wants to estimate the average number of conference rooms rented daily in each month. The population of conference rooms rented daily is assumed to be normally distributed for each with a standard deviation of 24 rooms. During January, a sample of 16 days has a sample mean of 48 rooms. This information is used to calculate an interval estimate for the population mean to be from 40 to 56 rooms. What is the level of confidence of this interval?

Select one:

a. 81.64%

b. 84.16%

c. 85.08%

d. 78.89%

e. 90.82%

9.A student must pass through 8 sets of traffic lights on his way to university each day. Suppose that each of the lights is green 40% of the time, yellow 10% of the time, and red 50% of the time. Suppose it is known that the traffic lights function independently. What is the probability that the student encounters exactly 4 red lights on his way to university one day?

Select one:

a. 0.7460

b. 0.5

c. 0.2734

d. 0.3628

e. 0.6367