Question is incomplete, however here's an explanation to solve questions such as this
Answer and explanation:
Probability= number of favorable outcomes/total number of outcomes
The frequency distribution recorded by the professor would show number of times(frequency) each student missed a class day.
We are required to fund the probability that a student would miss class
Probability = number of times the student missed class/ total number of classes missed by all students
Example, if student missed class 20 times in a semester and all students in total missed class 200 times
Probability that the student would miss class=20/200= 1/10