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# Probability

### Probability

The time required to complete a project is known to be normally distributed with a mean of 44 weeks and a standard deviation of 8 weeks. a) What is the probability that the project is finished in 40 weeks or fewer? b) What is the probability that the project is finished in 52 weeks or fewer? c) There is an 95 percent cha

### Calculate the standard deviation of the returns.

1. Buxton Corporation is planning to invest in a security that has several potential rates of return. Using the following probability distribution of returns during different states of the economy, what is the expected rate of return on this investment? In addition, compute the standard deviation of the returns. Finally, briefly

### Probability - normal distribution

1. If a fair coin is tossed 20 times then the probability of exactly 10 Tails is more than 15 percent. 2. The fill weight of a certain brand of adult cereal is normally distributed with a mean of 910 grams and a standard deviation of 5 grams. If we select one box of cereal at random from this population, what is the probabili

### Normal distribution

Very difficult subject material for me. 1. Given a normal distribution with mean=100 and variance/S.D. = 10, what is the probability that a. X>75? B. X<70? C. X<80 or X>110? D. Between what two X values (symmetrically distributed around the mean) are 80% of the values? 2. A statistical analysis of 1,000 long-distance tele

### math 5

** Please see the attached file for the complete problem description ** 1. Find the Expected Value, the Variance and the Standard Deviation for the random variable with the following probability distribution: (please see the attached file) 2. Calculate the following expressions with factorials: a) 5! b) 6!/4! 3. Us

### Independence and covariance

This is a two part question. The first part is setting the average of two 'independent' dice rolls to be a random variable (RV). The expected value and variance are asked. The second part deals with the notion that just because two independent RV have no correlation, the opposite is not generally true. Independence and corre

### Probabilities from written description

Over 1,000 people try to climb Mt. Everest every year. Of those who try to climb Everest, 31% succeed. The probability that a climber is at least 60 years old is .04. The probability that a climber is at least 60 years old and succeeds in climbing Everest is .005. (a) Find the probability od success, given that a climber is

### Understanding probabilities in a given situation

Half of a set of the parts are manufactured by machine A and half by machine B. Four percent of all the parts are defective. Six percent of the parts manufactured on machine A are defective. Find the probability that a part was maufactured on machine A, given that the part is defective. Explain your reasoning clearly. Please

### Tree diagram from written description

A study showed that 60% of The Wall Street Journal subcribers watch CNBC every day. Of these, 70% watch it outside the home. Only 20% of those who don't watch CNBC every day watch it outside the home. Let D be the event "watches CNBC daily" and O be the event "watches CNBC outside the home." (a) Sketch a tree based on this dat

### Probability Distributions- Graduate Studies Level

I encourage you to use PHStat as much as possible and attach PHStat outputs to your work. No manual calculation is required. [1] As reported by Runner's World magazine, the times of the finishers in the New York City 10-km run are normally distributed with a mean of 61 minutes and a standard deviation of 9 minutes. Let x be t

### Probability

3. Historically, demand for a product has been normally distributed. You collect 12 months of demand data (shown in Demand tab). Use this data to estimate your population parameters. a. What is the probability that demand will be equal to the mean? b. What is the probability that demand will be less than the mea

### Probability Concept Scenarios

Please help me to check my answers to the following questions. Please show your work so that I may follow and compare against my own: a) In how many ways can seven banquet speakers be seated along one side of the head table? b) Gym lockers are to be numbered from 1 to 99 using individual metal number plates to be

### Test slow paying accounts for a local wholesaler

The slow paying accounts for a local wholesaler are normally distributed with a mean of 20 accounts and a standard deviation of 4 accounts. What is the probability of randomly selecting an account and finding that it is slow? What is the probability of selecting an accounting period that has more than 25 slow paying accounts

### Statistics: Within what range would 85% of credit score fall

The credit score of a 35 applying for a mortgage is normally distributed with a mean score of 600 and a standard deviation of 100. What credit score defines the top five percent of scores. Within what range would 85% of credit score fall. One hundred car tires are tested and the mean useful life comes out to 50,000 and the

### Probability of Correctly Selecting Winning Lottery Numbers

A certain state is contemplating creating a weekly lottery, the revenues from which will be used to fund improvements in the state's public education system. The commission chartered to develop the guidelines for the proposed lottery envisions using a process whereby six (6) balls will be randomly selected from a single bin cont

### Proportion of male college students at specific heights

Assume that the population of heights of male college students is approximately normally distributed with mean m of 70 inches and standard deviation s of 3.75 inches. Show all work. (A) Find the proportion of male college students whose height is greater than 68 inches. (B) Find the proportion of male college students who

### Statistics: Five Probability multiple choice questions

1. A kindergarden class consists of 14 boys and 11 girls. If the teacher selects children from the class using random sampling: a. what is the probability that the first child selected will be a girl? b. if the teacher selects a random sample of n=3 children and the first two children are both boys, what is the probability

### Mean Variance Probability: The Duration of a Phone Call

** Please see attached file for the complete problem description ** The duration T of a certain type of phone call is found to satisfy (please see the attached file) where (please see the attached file). Find the mean and variance of T. If two independent calls are made, what is the probability that their combined duration

The reading speed of second grade students in a large city is approximately normal, with a mean of 91 wpm and standard deviation of 10 wpm. (a) What is the probability a randomly selected student in the city will read more than 95 wpm? (b) What is the probability that a random sample of 11 second grade students from the ci

### Probability distribution for random driver vs number of speeding tickets in last two years

Choose an American driver at random and let the random variable X be the number of speeding tickets the driver has received in the last two years. The discrete probability distribution of X is shown. Tickets 0 1 2 3 4 5 Probability 0.16 0.32 0.25 0.12 0.09 0.06 (2) Verify the two main requirements that mak

### Probabilities of Participants for Apple Products by Age

In a recent survey, participants were asked which Apple products influenced them the most. ipod iphone ipad total Age under 20 70 100 130 300 Age 20-40 160 140 90 390 Age over 40

### Finding Probability and Confidence Intervals

Of the members of a Boy Scout troop, 15% have received the first aid merit badge. If 40 boy scouts are selected at random, find the probability that four or more will have the first aid merit badge? A) 86.6% B) 81.3% C) 36.6% D) 31.3% A food snack manufacturer samples 9 bags of pretzels off the assembly line and weig

### Calculating desired probability values

Z is the standard normal random variable that is, the normal random variable with mean 0 and standard deviation 1. Use the table values in your textbook to determine the following a. The probability that z is less than -2.12. b. The probability that z is greater than 1.57. c. The probability that z is between -1.84 and

### Normally distribution

The diameters of grapefruits in a certain orchard are normally distributed with a mean of 6.95 inches and a standard deviation of 0.75 inches. Show all work. (A) What percentage of the grapefruits in this orchard have diameters less than 6.6 inches? (B) What percentage of the grapefruits in this orchard are larger than 6.

### Probability and Distributions

I need some guidance or a template to use to help me with this project. Calculations would be helpful if not a template. This is the assignment: "Using our data set from Unit 1, compose a 3-page e-mail to the head of the American Intellectual Union, which includes the following: 1.Begin your e-mail to AIU by first provid

### Stats Question 6

A certain law school claims that 75% of its graduates pass the state bar exam on their first attempt . . . keep in mind that these are lawyers, so the claims may not be true. If we assume that the claim is true, then if a sample of N=60 graduates is selected, find the probability that: a. 48% or more pass on the first attempt

### Probability of Unmarried Couples

Fifty-Four percent of a bank's credit card applications come from unmarried people. If s sample of N=150 applications is selected, find the probability that 90 or fewer are unmarried. (Remember continuity correction).

### Statistical Analysis on Weight of Filled Packages

A pet food manufacturer uses an automatic process to fill packages, which have a nominal weight of 40 pounds. Supposed that the actual weight is a normally distributed variable, with a mean of 40.9 pounds, and a standard deviation of 0.5 pounds. a. What proportion of the individual bags contains less than 40 pounds? b. If a

### Satisfactory and Unsatisfactory Production Probability

At a factory that produces pistons for cars, Machine 1 produced 414 satisfactory pistons and 276 unsatisfactory pistons today. Machine 2 produced 420 satisfactory pistons and 180 unsatisfactory pistons today. Suppose that one piston from Machine 1 and one piston from Machine 2 are chosen at random from today's batch. What is the

### Statistics: Contingecy table, probability distribution, portfolio expected return, Poisson distribution, normal distribution, standard deviation

See attached file for format and formulas. Q4: 4 (+) Given the following contingency table: B B' A 10 30 A' 25 35 Find the following: a) A | B b) A' | B' c) A | B' Q4: 5 The manager of a large computer network has developed the following proba