Question

ter 5 Jessica Salmeron-Uribe Due in 3 hours, 57 minutes. Due Wed 07/29/2020 11:59 pm Data were collected from a survey given to graduating college seniors on the number of times they had changed majors. From that data, a probability distribution was constructed. The random variable X is defined as the number of times a graduating senior changed majors. It is shown below: 2 0 3 4 5 7 8 P(X-2) 0.244 0.273 0.1890.166 0.066 0.038 0.019 0.003 0.002 a. What is the probability that a randomly selected student changed his or her major at least once? Preview b. What is the probability that a randomly selected student changed his or her major at most twice? Preview c. Given that a randomly selected person did change majors, what is the probability that he or she changed majors more than three times? Preview License Points possible: 1 This is attempt 1 of 3 Submit

Answer 1

a) P( changed his/her major at least once)= P( X >=1)

= 1- P( X =0)

= 1- 0.244

= 0.756

b) P( changed his/her major at most twice) = P( X <=2)

= P( X=0) + P(X=1) + P(X=2)

= 0.244 + 0.273 + 0.189

= 0.706

c) P( Changed her major more than 3 times | did change major)

= P( X >3 | X >0)

= P( X >3 n X >0) / P( X>0)

= P( X>3) / P(X>0)

= [P(X=4) + P(X=5) + P(X=6) + P(X=7) + P(X=8) ] / [ 1- P(X=0) ]

= [ 0.066 + 0.038 +0.019 +0.003 +0.002] / [ 1- 0.244]

= 0.128 / 0.756

=0.1693