Q. If a fair die is rolled 4 times, what is the probability, rounded to the nearest thousandth, of getting at most 1 two?Answer:
Calculate Probability of Not Rolling Two: Determine the probability of not rolling a two on a single die roll.A fair die has 6 sides, so the probability of rolling any specific number, including a two, is 61. Therefore, the probability of not rolling a two is 65.
Calculate Probability of Not Rolling Two in Four Rolls: Calculate the probability of not rolling a two in all four rolls.Since each roll is independent, we multiply the probability of not rolling a two for each roll.(65)×(65)×(65)×(65)=(65)4
Calculate Probability of Rolling Exactly One Two: Calculate the probability of rolling exactly one two in four rolls.We need to consider all the different positions the two can appear in, which is 4 (first, second, third, or fourth roll). The probability for each scenario is (1/6) for rolling a two and (5/6) for not rolling a two in the other three rolls.4×(1/6)×(5/6)×(5/6)×(5/6)=4×(1/6)×(5/6)3
Add Probabilities of No Twos and Exactly One Two: Add the probabilities of rolling no twos and exactly one two.This will give us the probability of rolling at most one two in four rolls.(5/6)4+4×(1/6)×(5/6)3
Perform Calculations: Perform the calculations.(65)4=(1296625)4×(61)×(65)3=4×(61)×(216125)=(1296500)Adding these together gives:(1296625)+(1296500)=(12961125)
Round Result: Round the result to the nearest thousandth. 12961125≈0.868
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