A deck of n cards numbered 1 through n are to be turned over one a time. Before each card is shown you are to guess which card it will be. After making your guess, you are told whether or not your guess is correct but not which card was turned over. It turns out that the strategy that maximizes the expected number of correct guesses fixes a permutation of the n cards, say 1, 2,. . ., n, and then continually guesses 1 until it is correct, then continually guesses 2 until either it is correct or all cards have been turned over, and then continuality guesses 3, and so on. Let G denote the number of correct guesses yielded by this strategy. Determine P ( G = k ) Hint: In order for C to be at least k what must be the order of cards 1,…,k.
A deck of n cards numbered 1 through n are to be turned over one a time. Before each card is shown you are to guess which card it will be. After making your guess, you are told whether or not your guess is correct but not which card was turned over. It turns out that the strategy that maximizes the expected number of correct guesses fixes a permutation of the n cards, say 1, 2,. . ., n, and then continually guesses 1 until it is correct, then continually guesses 2 until either it is correct or all cards have been turned over, and then continuality guesses 3, and so on. Let G denote the number of correct guesses yielded by this strategy. Determine P ( G = k ) Hint: In order for C to be at least k what must be the order of cards 1,…,k.
Solution Summary: The author calculates the probability of P(G=K), where G is the number of correct guesses.
A deck of n cards numbered 1 through n are to be turned over one a time. Before each card is shown you are to guess which card it will be. After making your guess, you are told whether or not your guess is correct but not which card was turned over. It turns out that the strategy that maximizes the expected number of correct guesses fixes a permutation of the n cards, say 1, 2,. . ., n, and then continually guesses 1 until it is correct, then continually guesses 2 until either it is correct or all cards have been turned over, and then continuality guesses 3, and so on. Let G denote the number of correct guesses yielded by this strategy. Determine
P
(
G
=
k
)
Hint: In order for C to be at least k what must be the order of cards 1,…,k.
4. (i) Let a discrete sample space be given by
N = {W1, W2, W3, W4},
and let a probability measure P on be given by
P(w1) = 0.2, P(w2) = 0.2, P(w3) = 0.5, P(wa) = 0.1.
Consider the random variables X1, X2 → R defined by
X₁(w1) = 1, X₁(w2) = 2,
X2(w1) = 2, X2 (w2) = 2,
Find the joint distribution of X1, X2.
(ii)
X1(W3) = 1, X₁(w4) = 1,
X2(W3) = 1, X2(w4) = 2.
[4 Marks]
Let Y, Z be random variables on a probability space (, F, P).
Let the random vector (Y, Z) take on values in the set [0, 1] x [0,2] and let the
joint distribution of Y, Z on [0, 1] x [0,2] be given by
1
dPy,z (y, z) ==(y²z+yz2) dy dz.
harks 12 Find the distribution Py of the random variable Y.
[8 Marks]
marks 11
3
3/4 x 1/4
1.
There are 4 balls in an urn, of which 3 balls are white and 1 ball is
black. You do the following:
draw a ball from the urn at random, note its colour, do not return the
ball to the urn;
draw a second ball, note its colour, return the ball to the urn;
finally draw a third ball and note its colour.
(i) Describe the corresponding discrete probability space
(Q, F, P).
[9 Marks]
(ii)
Consider the following event,
A: Among the first and the third balls, one ball is white, the other is black.
Write down A as a subset of the sample space and find its probability, P(A).
[2 Marks]
There are 4 balls in an urn, of which 3 balls are white and 1 ball isblack. You do the following:• draw a ball from the urn at random, note its colour, do not return theball to the urn;• draw a second ball, note its colour, return the ball to the urn;• finally draw a third ball and note its colour.(i) Describe the corresponding discrete probability space(Ω, F, P). [9 Marks](ii) Consider the following event,A: Among the first and the third balls, one ball is white, the other is black.Write down A as a subset of the sample space Ω and find its probability, P(A)
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, probability and related others by exploring similar questions and additional content below.
Discrete Distributions: Binomial, Poisson and Hypergeometric | Statistics for Data Science; Author: Dr. Bharatendra Rai;https://www.youtube.com/watch?v=lHhyy4JMigg;License: Standard Youtube License