Answer:
The answer to the question is;
The number of papers expected to be handed in before receiving each possible grade at least once is 14.93.
Step-by-step explanation:
To solve the question , we note that it is a geometric distribution question which have equal probabilities and therefore is a form of Binomial distribution with Bernoulli trials, where we are conducting the trials till we have r successes
Since we have r = 6, we will have to find the expected value of the number of trials till the nth paper handed in receives a previously awarded grade.
We therefore have,
The Probability that out of six papers turned 5 are different scores is given by
P(Y=5) = p'= q⁵p = (1-p)⁵p = 3125/46656
Therefore p' = the probability of receiving different grades once then the expected value is given by
E(X) = 1/p' = 46656/3125 = 14.93.
