To find the difference between the experimental probability and the theoretical probability of getting 3 tails from flipping 3 pennies, we can follow these steps:
-
Calculate the experimental probability:
- You flipped the pennies 100 times and got 3 tails 40 times.
- Experimental probability of getting 3 tails = (Number of times you got 3 tails) / (Total number of trials) = 40 / 100 = 0.4
-
Calculate the theoretical probability:
- When flipping a penny, each side (heads or tails) has an equal probability of landing face up, which is \( \frac{1}{2} \).
- The probability of getting 3 tails in a row (all tails) is: \[ P(\text{3 tails}) = \left(\frac{1}{2}\right)^3 = \frac{1}{8} = 0.125 \]
-
Find the difference between the experimental and theoretical probabilities:
- Difference = Experimental Probability - Theoretical Probability
- Difference = 0.4 - 0.125 = 0.275
Therefore, the difference between the experimental probability of getting 3 tails and the theoretical probability is 0.275.