1 A guidance counselor at a middle school collected the following information regarding the employment status of married couples within his school district.

Data Table

	0 children	1 child	2 or more children	Total
Only Spouse #1 Works	172	79	174
Only Spouse #2 Works	94	17	15
Both Spouses Work	522	257	370
Total

(round all probability answers to 3 decimal places)

For a randomly selected couple, what is the probability that both spouses work?

For a randomly selected couple, what is the probability that a couple has only 1 child?

For a randomly selected couple, what is the probability that a couple has two or more children AND both spouses work?

For a randomly selected couple, what is the probability that a couple has no children OR only spouse #1 works?

Would it be unusual to select a couple at random for which only spouse #2 works?

(yeso

2 Forty-three percent of marriages end in divorce. You randomly select 15 married couples. Calculate the following probability:

(round to 4 decimal places)

P(at least 2 married couples ends in divorce)

3 Supposeanexamconsistedof20multiplechoiceproblems,eachwithfourpossibleresponses(A-D), only 1 of which is correct.

Round all answers to 5 decimals.

Ifastudentrandomlyguessestheanswerstoeachquestionthenwhatistheprobabilitythatastudent guesses the correct answer to at most 13 questions?

What is the probabilitythat a student passes the exam with a score of 70% or higher?

4 The graph below represents a binomial distribution with n=10 trials. What possible value for the probability of success, p, could this represent? p=0.2 p=0.5 P=0.8

0.35 0.3 0.25 0.2 P(x) 0.15 0.1 0.05 0 0 1 2 3 4 5 6 7 8 9 100.35 0.3 0.25 0.2 P(x) 0.15 0.1 0.05 0 O 2 3 4 5 6 8 9 10 X0.3 0.25 0.2 P(x) 0.15 0.1 0.05 0 0 1 2 3 4 5 6 8 9 10