A recent survey shows that 60 of families regularly schedule

A recent survey shows that 60% of families regularly schedule family vacations for the month of April. Find the probability that at least 5 out of 8 randomly selected families regularly schedule family vacations for the month of April.

Select one:

a. .595

b. .279

c. .164

d. .209

9.

Assume a procedure yields a binomial distribution with a trial repeated 6 times. Using Table A-1, find the probability of 0 successes given that the probability of success on a single trial is 20%

Select one:

a. .118

b. .198

c. .393

d. .262

10.

35% of American households subscribe to TIVO. Suppose that 12 American households are randomly chosen. (Answer both parts for full credit.)

a) How many of them would you expect to have TIVO?

b) What is the probability that 2 OR 3 of them have TIVO?

Solution

X = no of families that plan for April vacation

X is binomial with p = 0.6 and n = 8(no of randomly selected families)

a) P(X>=5) = 0.5941.

Option a

9) P(X=0) for p = 0.2 and n =6

is 0.2621

Option d

10) a) Expected value of TIVO = np = 12(0.35)

= 4.20

--------------------------------

b)P(x=2 or 3) = P(X=2)+P(X=3)

=0.1088+0.1954

= 0.3042