The probability that a student has a GPA between 3.0 and 3.49 or prefers a Mac is 251/503.
The total number of students in the survey is 503.
The number of students with a GPA between 3.0 and 3.49 is 91.
The number of students who prefer a Mac is 160.
To find the probability that a student has a GPA between 3.0 and 3.49 or prefers a Mac, we need to add the number of students in each category and then divide by the total number of students.
Probability = (Number of students with GPA between 3.0 and 3.49 + Number of students who prefer a Mac) / Total number of students
Probability = (91 + 160) / 503
Probability = 251 / 503
Therefore, the probability that a student has a GPA between 3.0 and 3.49 or prefers a Mac is 251/503.