Probability and Data — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. A spinner landed on red 8 of 20 spins. About how many reds in 100 spins?
A) 40
B) 30
C) 20
D) 60
Eight reds per twenty spins is the same rate as forty reds per one hundred spins.
2. A bar graph shows 7 dogs, 4 cats, and 9 birds. How many pets total?
A) 18
B) 20
C) 21
D) 19
Adding seven, four, and nine gives a total of twenty pets in the graph.
3. If 3 of 12 marbles are green, what is the probability of green?
A) 1/2
B) 1/3
C) 1/4
D) 1/6
Three twelfths reduces to one fourth, so the probability is one over four.
4. A tally chart shows 4 bundles and 2 extras. What is the count?
A) 20
B) 24
C) 26
D) 22
Four bundles equal twenty, plus two extras, equals a total of twenty-two marks.
Part B: Fill in the Blank
Write the correct answer on each line.
1. If 6 of 30 spins land blue, predicting 100 spins gives about 20 blues.
Six per thirty is the same as twenty per one hundred when scaled equally.
2. A bag has 5 red and 5 yellow. Probability of red equals 5/10.
Five reds out of ten total give a probability fraction of five over ten.
3. A bar graph shows 12 boys and 8 girls. The total students count is 20.
Combining the two bars gives the total count of students in the data.
4. A tally chart of 7 bundles and 3 extras totals 38.
Seven bundles equal thirty-five, plus three more, equals thirty-eight marks.
5. If 4 of 16 cards are stars, the probability of star simplifies to 1/4.
Four sixteenths reduces to one fourth using a common factor of four.