The experiment involved tossing three coins simultaneously. The experiment was carried out 100 times, and it was noted that three heads occurred 40 times. What is the difference between the experimental probability of getting three heads and its theoretical probability? Write the answer in the simplest form of fraction.(1 point)

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1 answer

To find the difference between the experimental probability and the theoretical probability of getting three heads when tossing three coins, we'll first calculate both probabilities.

  1. Theoretical Probability:

    • When tossing three coins, the total number of outcomes is \(2^3 = 8\) (each coin has 2 outcomes: heads or tails).
    • Among these outcomes, there is only 1 outcome that results in three heads (HHH).
    • Therefore, the theoretical probability \(P\) of getting three heads is:

    \[ P(\text{three heads}) = \frac{1}{8} \]

  2. Experimental Probability:

    • In this experiment, three heads occurred 40 times out of 100 trials.
    • Thus, the experimental probability \(P_e\) is:

    \[ P_e = \frac{40}{100} = \frac{4}{10} = \frac{2}{5} \]

  3. Calculate the difference:

    • We need to find the difference between the experimental probability and the theoretical probability:

    \[ \text{Difference} = P_e - P = \frac{2}{5} - \frac{1}{8} \]

    • To subtract these fractions, we need a common denominator. The least common multiple of 5 and 8 is 40.
    • Convert each fraction:

    \[ \frac{2}{5} = \frac{2 \times 8}{5 \times 8} = \frac{16}{40} \] \[ \frac{1}{8} = \frac{1 \times 5}{8 \times 5} = \frac{5}{40} \]

    • Now subtract:

    \[ \frac{16}{40} - \frac{5}{40} = \frac{16 - 5}{40} = \frac{11}{40} \]

Thus, the difference between the experimental probability of getting three heads and its theoretical probability in simplest form is:

\[ \frac{11}{40} \]