Statistics and Probability Answers

A population has a mean of 20 and a standard deviation of 5.4. A simple random sample of size 35 will be taken and the sample mean will be used to estimate the population mean. Specify the sampling distribution of X bar. (X with a bar above it)

A bag contains five green marbles and three red marbles. If three marbles are chosen at random without replacement, what is the probability that all three will be green?

You are playing Texas Hold ‘em. For your two card hand, you receive an Ace and a King. This is a good hand to start with, and there are many ways it can become a very good hand. In particular, you can make three-of a kind, where the cards dealt on the board include two kings or two aces, making three total, including the ones in your hand.
a. What is the probability that there are exactly two kings dealt on the flop? That is, what is the probability that two kings are amongst the first three cards dealt?
b. Given your answer to a, what is the probability that there are two kings or two aces on the flop?

How do I figure out if the respondents in my data set agree or not? The most used measure is standard deviation, but I'm in doubt whether I can do that when my index variables are scale (consist of answers to a number of questions). My question is how do I measure the dispersion in order to figure out whether the population agree when I have a scale variable?

Hi, I need help with a homework question that I am working on. The answer and how you came to the answer would be very helpful. This is the question:

Assume a binomial probability distribution with n = 40 and π = .55. Compute the following:
a. The mean and standard deviation of the random variable.
b. The probability that X is 25 or greater.
c. The probability that X is 15 or less.
d. Thr probability that X is between 15 and 25, inclusive.

Thanks!

A researcher knows that the probability that a person will respond his letter is 10% If the researcher sends a post-paid letter the probability that the reciever will respond is 40%. The researcher sends 5 post-paid letters and 5 non post-paid letters. What is the probability that he recieves less then 3 responses?

Answer should be : 0,5193 How can you calculate this?

in a game show the contestant is shown is 10 boxes,3 of which contain prizes.If a contestant is allowed to select any three boxes then what is the probability that
(1):- The contestant wins all the prizes.
(2):- Only one selected box contains prize.

2) Suppose there are 400 possible points to earn in an economics class. For the purposes of this problem, we’ll assume that there are only 4 possible outcomes. The Distribution Function is given as the following:
Score F(S)
250 .1
300 .4
350 .75
400 1

A) What is the expected value for the score? What is the variance of the score?
B) These scores can be also converted into percentages. What is the expected percentage score? What is the variance of the percentage score? (We will learn a trick for calculating these quickly in the next sectaion of the class. But for now just use reason.)

a man and a women appear in an interview for two vacancies in the same post. the probability of mans selection is 1/4 and that of women s selectionis 1/3 the probability that none of them will be selected is- (a) 1/2 (b) 1/12 (c) 1/4 (d) none of these

A college basketball player who sinks 75% of her free throws comes to the line to shoot a “ one and one” ( if the first shot is successful, she is allowed a second shot, but no second shot is taken if the first is missed; one point is scored for each successful shot). Assume that the outcome of the second shot, if any, is independent of that of the first. Find the expected number of points resulting from the “ one and one.” Compare this with the expected number of points from a “ two- shot foul,” where a second shot is allowed, irrespective of the outcome of the first.