Question

1 A science teacher presented a balloon to his class, and posed the question, "If I keep this balloon in the freezer overnight, what will occur?" He followed up with, "How certain are you of your answer?" The teacher recorded his students' responses. Certain Uncertain 5 7 Shrink Stay the same Expand 11 15 4 4. What is the probability that a randomly selected student believes the balloon will expand or was certain? Simplify any fractions.

Answer 1

First let's draw the table:

Then, let's find the total number of students that answered the question by adding each element in the table:

$\text{total}=5+7+11+15+4+4=46$

The number of students that believe the balloon will expand is 4 + 4 = 8, and the number of students that are certain is