Question
Louis rolls a biased dice 100 times. The probability that he will roll a 4 is (2)/(5) The probability that he will roll a 5 is 0.23 How many more times would you expect Louis to roll a 4 than a 5 ?
Answer
4
(192 Votes)
Benjamin
Professional · Tutor for 6 years
Answer
17
Explanation
This question is related to probability and expected value. Since the dice is biased, the probability of getting each number isn't the same. The probability of rolling a 4 is 2/5 and the probability of rolling a 5 is 0.23.We know that:1. Expected value(E) of an event = (number of trials) * (probability of each event).2. The number of trials in this case Louis rolling the dice is 100 times.3. So the expected number of times Louis rolls a '4' = (number of trials * probability of getting a '4') =100 * 2/5 = 40 times,4. Similarly, the expected value / number of times Louis rolls a '5’ = (number of trials * probability of getting a '5') = 100 * 0.23 = 23 times.5. Hence, The extra times you would expect Louis to roll a 4 than a 5 = expected number of times Louis rolls a '4' - expected number of times Louis rolls a '5’= 40 - 23 = 17 times