Answer
a) He carried the observation with different students instead of one. For a good research outcome one should have as many tests as possible. By using 10 students, that was an advantage in his observation.
b) 30 minutes was a very short time. He could have increased the time he took with each student. It takes more than 30 minutes to complete a single homework. So if it was possible to take more time with a single student, it could be better.
<em>c) </em><em>10 students.</em>
<em>d) </em><em>30%</em>
3 students out of 10 used social media while doing their homework.
That is : 3/10 × 100 = 30%.
30% of high school students use social media while doing homework.
