Quantitative Methods
Hello Brainmass: Please answer the attached 60 Quantitative methods questions (some are t or f, some are multiple choice). This would be a great study guide for me.
Hello Brainmass: Please answer the attached 60 Quantitative methods questions (some are t or f, some are multiple choice). This would be a great study guide for me.
1. If the moment generating function ( mgf ) of X is (a) Find the mean of X. (b) Find the variance of X. (c) Find the pdf of X. 2. The joint probability mass function for random variables X and Y is: FXY (x, y) =(x + y)/32; x = 1, 2; y = 1, 2, 3, 4 (a) Show that fXY is a valid mass function. (b) Find the mar
The U.S. Bureau of Labor Statistics collected data on the occupations of workers 25 to 64 years old. The following table shows the number of male and female workers (in millions) in each occupation category (Statistical Abstract of the United States: 2002) (see chart in the attached file) a. Develop a joint probability tab
1. A door to door salesperson believes that the probability of making a sale when a person is at home is 0.4 he visits 10 homes. When someone is at home find the probability of making a) exactly 7 sales b) more than 7 sales 2.For a binomial distribution with an n=200 and p=0.3 calculate the probability of obtaining between 50
Let K(u) be a probability density function symmetric about zero. Please show; integral f(x) dx =1.
Describe three ways distributions can be represented (other than in a table that lists values for X and f(x)).
Indicate whether the sentence or statement is true or false. T 1. Deterministic techniques assume that no uncertainty exists in model parameters. F 2. The probabilities of mutually exclusive events sum to zero. T 3. A joint probability is the probability that two or more events that are not mutually exclusiv
1. (a) Roll a 6-sided die and then flip a coin the no. of times shown by the die. Letting Y be the no. of these flips coming up heads. What is E[X] and var(X)? (b) Repeat part a assuming first rolling two dice.
There's 4 6-sided dice rolled independently. Set Y1 to be sum of the numbers on the first and second dice, Y2 to be sum of numbers on the third and fourth dice. Convolve PMFs of Y1 & Y2 to find the probability of the outcome of the 4 rolls summing to be 8.
A & B are 2 independent normal random variables. A ~ N(0, σ2a); B ~ N(0, σ2b) Set C = A + B with C being normal. fC|A(c|a) is normal. Prove that conditional density fA|C(a|c) is normal for all values of y.
Person takes bus & subway to work. Bus runs every 20 min (X) & subway every 4 min (Y). Assume timing of the bus and subway are independent and uniform. ------------------ Please help find the joint and marginal distributions for this problem. Since they are independent I know that f(x,y) = fx(x) * fy(y) but do not understand
A couple has three children, assume the likelihood of a boy is the same as a girl: List sample space: {BBB,BBG,BGG,GGG} Event the children are grils: {GGG} Event the couple has one or more boy: {BBB,BBG,BGG} Probability all children are girls: 1/4 Probability the couple has at least one boy: 3/4 Probability the couple ha
1) The manager of a fast food restaurant determines that the average time that her customers wait for service is 2.5 minutes. a) Find the probability that a customer has to wait for more than 4 mintues. b) Find the probability that a customer is served within the first 2 minutes. Now, this was all worked out, but some ste
To determine expectation of bivariate random variable using joint probability function.
See attached and solve for 1, 3, 5 and 9 only. Give step by step solution with every minor detail.
Among the professionals you have interviewed for your article , were several state and federal government spokespersons who use linear equations in a variety of ways. 1. An employee of the National Parks service told you about a location in Washington , DC. It is a large grassy
One of the civil engineers you interviewed for your article works for a company which specializes in bridge construction projects. In the process of designing suspension bridges, they must account for many variables in the modeling. Some of these variables include the bridge span; the force of the typical water currents wear
9. The price-to-earnings (PE) ratio of a stock is the ratio of a stock's most recent price per share to the stock's earnings per share (averaged over a 12-month period). Listed below are the PE ratios for 40 randomly selected securities traded on the New York Stock Exchange (NYSE) on Wednesday, August 24, 2005. Stock PE R
A committee consists of 8 married couples. In how many ways can a subcommitee of 5 people be chosen so that at most one married couple belongs to the subcommittee?
1. Each of the three measures of central tendency-the mean, the median, and the mode-are more appropriate for certain populations than others. For each type of measure, give two additional examples of populations where it would be the most appropriate indication of central tendency. 2. Find the mean, median, and mode of
See the attached file. Fort Lost-in-the-Woods is a basic training center for new Army recruits. Upon arriving at the military post the new recruits are processed through the Induction Center that involves three steps: background information gathering, medical examination, and barracks assignment. Arriving inductees first enter
1. Each of the three measures of central tendency-the mean, the median, and the mode-are more appropriate for certain populations than others. For each type of measure, give two additional examples of populations where it would be the most appropriate indication of central tendency. 2. Find the mean, median, and mode of th
A4. A4. Let X be a discrete random variable with range RX = {1, 2, ...}. (a) Show that ..... (b) Suppose that X has probability mass function (pmf) .... (i) Find the cumulative distribution function (cdf) of X. (ii) Use (a) to find E(X). IMPORTANT: Could you please add at the end of the question a list of formulae under
A secretary periodically checks to see how mnay of the three lines into the office are busy. Her findings for one week were the following: No. Lines busy Frequency 0 20 1 65 2 25 3
A student applies for two different scholarships. The probability of receiving the first scholarship is 0.3 and the probability of receiving the second is 0.4. The decisions are made independently. Find the probability the student receives exactly one scholarship. A. 0.12 B. 0.42 C. 0.46 D. 0.40
If the probability that at least one person makes an A on the final exam is 0.15, then the probability no one makes an A is: A. 0.15 B. 0.65 C. 0.85 D. 0
A computer store has 10 copies of a word processing program, 12 copies of a spreadsheet program, and 8 copies of a draw program. Three of the word processing, four of the spreadsheet and two of the draw programs are infected with a computer virus. If a program is selected at random, the probability it is infected with a virus
The sample space of an experiment is {A, B, C, D} and P(A) = 0.1, P(B) = 0.3, P(C) = 0.4, P({A, C}) = A. 0.4 B. 0.5 C. 0.6 D. 0.8
A random variable y has a Rayleigh distribution, if and only if its probability distribution is given by: f(y)=2(alpha)y^(-alpha y^2) , y>0 and alpha>0 f(y)=0 , elsewhere a) Show that mean=(1/2)*squareroot(pi/alpha) b) Show that the variance =(1/alpha)*(1-pi/4)
A Recent survey indicates that the average salary of all entry-level women managers in St. Paul is $56,700 with a standard deviation $7,200. What is the probability that a random sample of 50 such women will yield a mean entry-level that exceeds $58,000?