okmarks Window Help Take Test 53 Online Homework MATH134201

okmarks Window Help Take Test: 5.3 Online Homework MATH-1342-01 Elementary... Updates Read Do you want to re utb blackboard.com/webapps/assessment/takellaunch,jsp?course assessment id 334416.1&course; id these updates now Twitter Wikipedia Yahoo News Popular a calculus studen Stats: Binomial 4 egg com suppose that onli Standard Deviati suppose that a family has 5 children and that the probability of having a girl is What is the probability of having exactly two girls and three boys? O 0.0625 O 0.6252 0.3125 0.0312 1 points Save Answer Question 2 Suppose that only 65% of all drivers in a certain state wear a seat belt. A random sample of 80 drivers is selected. What is the probability that exactly fifty-drivers wear a seat belt? O 0.36 O 0.92 O 0.08 0.64 1 points Question 3 Save Answer A calculus class has 120 members and 10x of the stuNe are usually absent. Find the mean, varianc and standard deviation (respectively) of the students usually absent. 12.1.20, 12, 13.33, 3.65 12, 10 B, 3.29 12, 15.50, 3.94 question 4 1 points solve the problem.

Solution

#2. P(X = 50) = (80 choose 50) * (.65)^50 * (.35)^30 = .08235. Answer is C.

#3. Mean = n*p = 120*0.1 = 12. Variance = n*p*(1-p) = 120*.1*.9 = 10.8. Standard deviation = sqrt(Variance) = 3.29. Answer is C.

You got the first one right, (5 choose 2)*(.5)^2 * (.5^3) = .3125