Probability and Data — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. Flipping two coins, the chance of two tails is 1 in 4.
Two coins have four outcomes total and TT is one of them, giving a one in four chance.
2. A 4-equal-sector spinner gives any one color a 1 in 4 chance.
Each equal sector has the same chance, so any single color is one out of four total sectors.
3. If 8 of 32 trials hit blue, experimental probability is 8 out of 32.
Experimental probability records what actually happened, so eight blue hits out of thirty-two trials gives eight.
4. Predict heads in 50 coin flips: about 25 heads.
Fifty flips times one half equals twenty-five expected heads, a fair theoretical prediction.
5. Two coins, chance of at least one head is 3 out of 4.
Three of four outcomes contain a head, so the probability is three out of four.
6. Spinner with 4 equal sectors red, red, blue, green: red chance is 2 out of 4.
Two red sectors of four equal sectors give a two in four chance for the color red.
7. In 20 rolls of a die, a six appeared 4 times; experimental chance is 4 out of 20.
Experimental probability comes from data, so four sixes in twenty rolls give four out of twenty.
8. If chance of green is 1 in 4, in 24 spins expect about 6 greens.
Twenty-four times one fourth equals six expected greens, a sound prediction from theoretical chance.
9. Two coins flipped 80 times, expect about 20 flips of two tails.
Eighty times one fourth equals twenty expected double tails, matching theoretical probability for compound events.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Sample space of two coins
→ Four outcomes HH HT TH TT
Four outcomes HH HT TH TT
Equal-sector spinner
→ Each sector equally likely
Each sector equally likely
Theoretical probability
→ Counted from possible outcomes
Counted from possible outcomes
Data-based prediction
→ Trials times probability fraction
Trials times probability fraction
Linking ideas to definitions strengthens probability vocabulary and supports students in solving new prediction or spinner problems.