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A fair die is rolled 36 times what is the standard deviation of the number 1 or 2 on the top face

User Koxta
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Final answer:

The standard deviation for rolling a 1 or 2 on a fair six-sided die 36 times is 2.828, calculated using the binomial standard deviation formula with a probability of success of 1/3.

Step-by-step explanation:

The student is asking about the standard deviation for obtaining a 1 or 2 on a six-sided die when rolled 36 times. Since each roll is independent, we can treat this as a binomial distribution problem, where the probability of success (rolling a 1 or 2) on a single trial (roll of the die) is P(success) = 1/3, as two out of the six possible outcomes are considered a success.

To find the standard deviation for a binomial distribution, we use the formula σ = √(n × p × (1-p)), where σ is the standard deviation, n is the number of trials, p is the probability of success on a single trial, and (1-p) is the probability of failure.

So, for 36 rolls:

  1. Calculate the probability of success: p = 1/3 (since there are two favorable outcomes, 1 and 2, out of six total outcomes)
  2. Calculate the number of trials: n = 36
  3. Use the binomial standard deviation formula: σ = √(36 × (1/3) × (2/3))
  4. Solve for σ: σ = √(36 × 1/3 × 2/3) = √(36 × 1/3 × 2/3) = √(8) = 2.828

Therefore, the standard deviation for the number of times a 1 or 2 appears on the top face after rolling a fair die 36 times is 2.828.

User Kousen
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