Elizabeth is going to flip a fair coin 100 times.What is the best prediction for the number of times that the coin will land tails up?Choose 1 answer:(A) Exactly 200 times(B) Close to 200 times but probably not exactly 200 times(C) Exactly 50 times(D) Close to 50 times but probably not exactly 50 times
Q. Elizabeth is going to flip a fair coin 100 times.What is the best prediction for the number of times that the coin will land tails up?Choose 1 answer:(A) Exactly 200 times(B) Close to 200 times but probably not exactly 200 times(C) Exactly 50 times(D) Close to 50 times but probably not exactly 50 times
Understand single event probability: We need to understand the probability of a single event first. A fair coin has two sides, heads and tails, so the probability of getting tails on a single flip is 21.
Expectation over large number: Since the coin is fair, we expect heads and tails to occur with equal frequency over a large number of flips. Therefore, we can predict that half of the flips will result in tails.
Calculate expected number of tails: To find the expected number of tails, we multiply the total number of flips by the probability of getting tails on a single flip. This is 100 flips ×21 probability of tails =50 expected tails.
Choose best answer from options: Now we need to choose the best answer from the options given. Option (A) "Exactly 200 times" is not possible because we are only flipping the coin 100 times. Option (B) "Close to 200 times but probably not exactly 200 times" is also incorrect for the same reason. Option (C) "Exactly 50 times" is a possibility, but due to the nature of probability, it is unlikely to be exactly 50 times. Option (D) "Close to 50 times but probably not exactly 50 times" is the most accurate prediction, as it accounts for the variability inherent in random events.
Best prediction for number of tails: Therefore, the best prediction for the number of times the coin will land tails up is close to 50 times but probably not exactly 50 times, which corresponds to option (D).