Tetrahedron Probability Lab Name______

Follow the directions carefully and answer all questions.

1. You have two regular tetrahedron templates. LABEL the faces of one of the tetrahedrons with the words YELLOW, RED, BLUE, and GREEN.

2. Fold the tetrahedron to form a four-sided die. Tape the sides. Note that there are tabs on the template to help with the taping.

3. Roll this “die” 20 times. Record how many time each color lands face down by placing a tally mark in the correct space in the table below. YELLOW RED BLUE GREEN

4. On the basis of your 20 rolls, does it appear that one color is more likely to land face down? ______If so, what color?______

5. Based upon your 20 rolls, express the probability (with a denominator of 20) that the GREEN face will land face down?______The RED face? ______The YELLOW face?______The BLUE face?______

What should be the sum of these four fractions?______

6. Roll your tetrahedron die another 20 times. Keep a record similar to the record from questions 3. Record your results below. YELLOW RED BLUE GREEN

7. Did you get approximately the same results?______

All Rights Reserved © MathBits.com 8. Now, combine the results of all 40 rolls of the tetrahedron die. Using a fraction whose denominator is 40, write the probability of each color landing face down on any given roll of the die. GREEN______RED______YELLOW ______BLUE ______

9. Was your rolling of this die a good, fair sampling? _____ Why, or why not?

10. Label the faces of the second tetrahedron template 1, 2, 3, 4. Fold and tape.

11. List all of the possible combinations of rolling these two die.

12. Roll your pair of tetrahedron dice 32 times. If YELLOW = 1, RED = 2, BLUE = 3, and GREEN = 4, record the sum of the faces of the dice that land face down. SUM TALLY Which sum appeared most often?______

In how many different ways is it possible to roll a 5? ______

What is the probability of rolling a 5? ______

Compute the probabilities of rolling each of the sums.

What do these probabilities add up to?______