Nathan conducted an experiment in which he spun a spinner with four equal-sized sections labeled W, X, Y, and Z. The results of his experiment are shown below.

Nathan's Experiment
Spin Result
1 W
2 X
3 Z
4 X
5 Y
6 Z
7 Y
8 W
9 X
10 X
Spin Result
11 Z
12 X
13 Y
14 X
15 W
16 Y
17 X
18 Y
19 Z
20 X

Which letter has an experimental probability equal to its theoretical probability?
A.
X
B.
W
C.
Z
D.
Y

1 answer

To find which letter has an experimental probability equal to its theoretical probability, we first need to determine the theoretical probability for each letter. Since the spinner has four equal-sized sections (W, X, Y, Z), the theoretical probability for each letter is:

  • P(W) = 1/4
  • P(X) = 1/4
  • P(Y) = 1/4
  • P(Z) = 1/4

Next, we need to calculate the experimental probabilities based on Nathan's results. We will count how many times each letter appeared and divide by the total number of spins (20).

Counting Results:

  • W: 4 times (Spins 1, 8, 15)
  • X: 7 times (Spins 2, 4, 9, 10, 12, 14, 17)
  • Y: 4 times (Spins 5, 7, 16, 18)
  • Z: 5 times (Spins 3, 6, 11, 19)

Calculating Experimental Probabilities:

  • P(W) = 4/20 = 1/5
  • P(X) = 7/20
  • P(Y) = 4/20 = 1/5
  • P(Z) = 5/20 = 1/4

Now we compare the experimental probabilities to the theoretical probabilities:

  • For W: Experimental (1/5) vs Theoretical (1/4) - Not equal
  • For X: Experimental (7/20) vs Theoretical (1/4) - Not equal
  • For Y: Experimental (1/5) vs Theoretical (1/4) - Not equal
  • For Z: Experimental (1/4) vs Theoretical (1/4) - Equal

The letter that has an experimental probability equal to its theoretical probability is C. Z.