Answer: Class 1 and Class 3 shows the correct prediction that atleast 78% of students chose digital source.
Explanation:
Since we have given that
There is a table showing number of students prefer getting their news from a digital source or a print source.
And we have mentioned that a professor predicted that at least 778 % of students prefer getting their news from digital source rather than from a print source.
From class 1, we get that
Number of students chose digital source = 20
Total number of students = 25
So, percentage of students prefer digital source is given by

Similarly, from class 2, we get that
Number of students chose digital source = 14
Total number of students = 24
So, percentage of students prefer digital source is given by

Similarly, From class 3, we get that
Number of students chose digital source = 30
Total number of students = 37
So, percentage of students prefer digital source is given by

Therefore, Class 1 and Class 3 shows the correct prediction that atleast 78% of students chose digital source.