QUESTION 15 Suppose that five balls, numbered 1 through 5, will be sequentially drawn (without replacement) from an urn at random (with all balls remaining in the urn being equally likely to be drawn...

R3

Extracted text: QUESTION 15 Suppose that five balls, numbered 1 through 5, will be sequentially drawn (without replacement) from an urn at random (with all balls remaining in the urn being equally likely to be drawn each time). If a success is said to occur if the number obtained on draw i is the largest of the i numbers drawn so far, what is the expected number of times a success will occur on the five draws? Suggestion: Use a random variable which is a sum of simple indicator random variàbles, and use symmetry to obtain the necessary probabilities.