91影视

We have to tell about type of sample did the counsellor obtain.

Because the student conveniently surveyed the first $100$students, the sample in the activity prompt is a text convenience sample convenience sample. A convenience sample is frequently text biased, because the first$100$persons will have slept less because they arrived earlier, whereas students who arrived later will have slept longer.

We have to tell about true average amount of sleep last night.

A convenience sample is frequently textbfbiased, because the first $100$persons will have slept less because they arrived earlier, whereas students who arrived later will have slept longer. We estimate the average of $7.2$hours to be less than the actual average because the first $100$students are likely to have slept less than the other pupils.