Kala rolled a number cube

500
times and got the following results.
Outcome Rolled
1
2
3
4
5
6
Number of Rolls
68
78
93
81
83
97
Fill in the table below. Round your answers to the nearest thousandth.
(a)From Kala's results, compute the experimental probability of rolling a
3
or
6
.
(b)Assuming that the cube is fair, compute the theoretical probability of rolling a
3
or
6
.
(c)Assuming that the cube is fair, choose the statement below that is true:
The smaller the number of rolls, the greater the likelihood that the experimental probability will be close to the theoretical probability.
The experimental probability will never be very close to the theoretical probability, no matter the number of rolls.
The larger the number of rolls, the greater the likelihood that the experimental probability will be close to the theoretical probability.

1 answer

To solve the given problem, we can follow the steps below:

(a) Compute the experimental probability of rolling a 3 or 6.

First, we need to find the total number of times a 3 or a 6 was rolled. According to the results:

  • Number of rolls of 3 = 93
  • Number of rolls of 6 = 97

Total number of rolls of 3 or 6: \[ 93 + 97 = 190 \]

Next, we find the experimental probability. Experimental probability of rolling a 3 or 6: \[ P(3 \text{ or } 6) = \frac{\text{Number of favorable outcomes}}{\text{Total number of rolls}} = \frac{190}{500} \]

Now we can calculate: \[ P(3 \text{ or } 6) = \frac{190}{500} = 0.38 \]

So, the experimental probability of rolling a 3 or 6, rounded to the nearest thousandth, is: 0.380.

(b) Compute the theoretical probability of rolling a 3 or 6.

For a fair number cube (6-sided die), each of the six outcomes (1, 2, 3, 4, 5, 6) is equally likely. The theoretical probability for any single outcome is: \[ P(\text{single number}) = \frac{1}{6} \]

To find the theoretical probability of rolling a 3 or a 6, we can add the probabilities of each outcome: \[ P(3 \text{ or } 6) = P(3) + P(6) = \frac{1}{6} + \frac{1}{6} = \frac{2}{6} = \frac{1}{3} \] Calculating it: \[ \frac{1}{3} \approx 0.333 \]

So, the theoretical probability of rolling a 3 or 6, rounded to the nearest thousandth, is: 0.333.

(c) True statement about experimental and theoretical probability.

The statement that is true is: The larger the number of rolls, the greater the likelihood that the experimental probability will be close to the theoretical probability.

This is due to the Law of Large Numbers, which states that as the number of trials increases, the experimental probability tends to get closer to the theoretical probability.