A teacher at a local high school surveyed the senior students. Two of the variables recorded for the 200 students were whether the student has any
siblings and whether the student typically drives to school. The following table
summarizes the responses. Choose a senior at random. Let D be the event that
the student drives to school and S be the event that the student has at least one
sibling
Yes
Yes
No
Total
80
50
Drive to School?
No Total
40
120
30
80
70
200
130
2 points
What is the probability that a randomly chosen senior from this high
school drives to school?