Refer to the demographic information shown to the right that has been collected
ID: 3136260 • Letter: R
Question
Refer to the demographic information shown to the right that has been collected by an instructor after surveying her class Total number of students in the class Number of boys 49 24 25 The instructor randomly chooses one student to pass out papers, one student to Number of oits clean the chalkboard, and one student to empty the trash If a student may not do more than one job, then what is the probability that the instructor will Number of Freshman choose at least one boy to do the jobs? Number of Sophomores Number of Juniors Number of Seniors 16 13 12 There is a [1% probability that the instructor wil choose at least one boy to do the jobs (Round the final answer to one decimal place as needed Round all intermediate values to three decimal places as needed )Explanation / Answer
probability to choose at least one boy = 1 - probability of no boy choosen
= 1 - all 3 are girls
probability to choose 3 girls = 25P3 / 49P3
= (25*24*23) / (49*48*47)
= 0.125 (ANSWER)