For families with 5 children, let XX be the number of children with Genetic Condition B. Can the following table be a probability distribution for the random variable XX? xx P(x)P(x) 1 0.2077 2 0.0943 3 0.3281 4 0.1105 5 0.3232 A. yes B. no

The random variable X can take on the values 2, 4 and 6, and the random variable Y can take onthe values 2, 6 and 10. Their joint probability distribution is given by the following table:Y2 6 10X2 0.10 0.05 0.104 0.10 0.15 0.256 0.10 0.10 0.05a. Describe in words and notation the event that has probability 0.25 in the table.b. Calculate the marginal distribution of X.c. Calculate ?ሺ? ൒ 4ሻ.d. Calculate the population mean of X.e. Calculate the conditional distribution of Y given X=2.f. Calculate E(Y|X=2).

Suppose you choose four people at random from a Statistics class in which you know 20% of the students have an A average. Let X be the number of students in your sample who have an A average. Obtain the probability distribution for X and plot the probability histogram. X Probability 0 i N 3 A 0.45 0.4 0.35 0.3 i Probability histogram: 0.25 i MI 0.2 0.15- 0.1 0.05- 0 0 1 2 X Figure 1. 3 0.45 0.4 0.35 0.3 0.25 m 10 el 02 0.15 0.1 0.05 0 0 2 X Figure 2. 3 0.45 0.4 0.35- 0.3- 0.25 02- 0.15 0.1- 0.05 0 0 1 2 X Figure 3. 3

As you walk into your econometrics exam, a friend bets you $10 that she will outscore you on the exam. Let ✗ be a random variable denoting your winnings. X can take the values 10, if you win teh bet, 0 if there is a score tie, or -10 if you lose. You know that the probability distribution for ✗ is denoted by f(x) and it depends on whether she studied for the exam or not. Let Y be the random variable that indicates if she studied, Y = 0 if she studied and Y = 1 if she did not study. The following table denotes the joint distribution of X and Y : Y=0 Y=1 f(x) X = -10 0.18 P1 P2 X = 0 0 P3 0.3 X = 10 P4 0.45 P5 f(y) P6 0.75 Probabilities P1, P2, P3, P4, P5, P6 are not displayed in the table. Answer the following items: (a) (b) (a) Compute the Probabilities P1, P2, P3, P4, P5, P6 of the table. (b) Compute the expectation E(X). Should you take the bet? (c) What is the probability distribution of your winnings if you know that she did not study, namely, P(X = −10|Y = 1), P(X = 0|Y = 1), P(X…