70 students responded to a survey documenting the amount of time spent

Let me see:

A) In order, to get the least possible value of the average number of TV viewing hours, lets assume that those people who watch less than 1 hour a day actually watch 0 hours. By doing this, we will effectively lower the average.

Let's calculate the average:

\(\frac{0(8)+1(4)+2(8)+3(9)+4(11)+5(11)+6(7)+7(8)+10(3)+11(1)}{70}\)

\(= \frac{285}{70} = 4.0714\)

So A must be 4.07

B) The respondents that watched less than 3/5 hrs a day watched less than\(\frac{{7*3}}{4} = 5.25\) hrs a week.

So the number of people who watched less than 5.25 hrs a week would include more or less those people to the left of the arrow below:



So for now, lets ignore the bar with the arrow.

The number of people to the left of the bar (excluding the bar) is:

8+4+8+9+11 = 40

Now, the bar with the arrow: 11 people watched at least 5 hours but less than 6hrs. If they did watch 5 hrs or less we can count them in our calculations. However, it is also possible that they could have watched 5.8hrs in which case we don't count them.

So our range is 40 (if we don't count them) to 51(if we do)