Explore BrainMass


Probability of individual being unemployed & high school dropout

In a depressed rustbelt city in Michigan, a newspaper investigative team found that a large majority of the city's youth were unemployed. The team defined youth as any city resident between the ages of 16-21. Of the population aged 16-21 and not in college, 13.5% are unemployed, 29.05 % are high school dropouts, and 5.32% ar

Probability: Are employment and economic trend independent?

Consider the following two economic characteristics with two possible outcomes each: employment (increase, decrease) and economic trend (positive, negative). Let the probability of a decreasing employment be 0.6 and the probability of a positive economic trend 0.5. Further, assume that the probability of a decreasing employment


1. According to the empirical rule, if the data form a "bell-shaped" normal distribution, ________ percent of the observation will be contained within 1 (one) standard deviation around the arithmetic mean. 68.26 75.00 88.89 93.75 2. The probability that a new advertising campaign will i

Probability of Defective Items from a Sample

A carton of 6 batteries contains 2 that are defective and 4 that are good. If we select 3 batteries at random form this carton, what is the probability that the sample contains exactly 1 defective battery? a) 33.3% b) 50.0% c) 60.0%


Suppose that a telemarketer calls a random sample of 12 households in a community in the night that 80% of the households have someone at home. Find the probability that the person doing the calling finds someone at home in exactly 10 households. a) 10.0% b) 28.3% c) 80.0% Find the mean of the above distribution. a)

Queuing Theory in a Barber Shop

A small barber shop has a single chair and an area for waiting, where only one person can be in the chair at a time, and no one leaves without getting their hair cut. So the system is roughly: Entrance Wait Haircut Exit Assume customers arrive at the rate of 10 per hour and stay an average of 0.5 hour. What is the average

Statistics: Relationship between students and credit cards

See tables in attached file. 1. (TCO 4) What is the probability that the student is a sophomore given he doesn't carry a credit card? 2. (TCO 4) Some students were asked if they carry a credit card. Here are the responses. What is the probability that the student didn't carry a credit card?

Loglinearand logit models

Find a loglinear model that describes this data well. Interpret associations then treating whether killed as the response, find an equivalent logit model. Interpret the effects. See attachment

Normal Probability: Time Taken to Travel from Home to Office

Question: The time it takes to travel from home to the office is normally distributed with u = 25 minutes and sigma = 5 minutes. a. What is the probability the trip takes more than 20 minutes? b. What is the probability the trip takes less than 15 minutes. c. What is the probability the trip takes between 30 and 35 minutes

General Statistics

13) We use the General Rule of Multiplication to combine A. Events that total more than 1.00. B. Events based on subjective probabilities C. Mutually exclusive events. D. Events that are not independent. 14) Which of the following is a correct statement about a probability? A. It may be greater than

Interpreting a Normal Distribiution of two different brands of soft drink

See attached file. You plan to conduct a marketing experiment in which students are to taste one of two different brands of soft drink. Their task is to identify the brand tasted. You select a random sample of 200 students and assume that the students have no ability to distinguish between the two brands. (Hint: if an individ

Resource: Statistical Techniques in Business & Economics

An internal study by the Technology Services department at Lahey Electronics revealed company employees receive an average of two emails per hour. Assume the arrival of these emails is approximated by the Poisson distribution. 1. What is the probability Linda Lahey, company president, received exactly 1 email between 4 P.M. and

Binomial Probability: Arrival of Northwest Airlines

Assume the likelihood that any flight on Northwest Airlines arrives within 15 minutes of the scheduled time is .90. We select four flights from yesterday for study. 1. What is the likelihood all four of the selected flights arrived within 15 minutes of the scheduled time? 2. What is the likelihood that none of the selected f

Binomial Probability for Automobile Parts Estimated to be Defective

A machine that manufactures automobile parts is estimated to produce defective parts 5% of the time. If this estimate is correct, and 9 parts produced by this machine are randomly selected, what is the probability that at most 2 turn out to be defective? Round your answer to four decimal places.

Statistics: Baseball, Northwest flight arrival, Lahey Electronics email

88. Refer to the Baseball 2005 data, which reports information on the 30 major league teams for the 2005 baseball season. a. Select the variable team salary and find the mean, median, and the standard deviation. b. Select the variable that refers to the age the stadium was built. (Hint: Subtract the year in which the stadium

Finding standard deviation and probability: Example questions

1. Population mean = 19.1 15% of data 22.6 Find standard deviation. 2. Population mean 120 Standard deviation 5.7 What is the probability an individual between 120 and 121.3? 3. Population mean 120 Standard deviation 5.3 Sample n =30 Find probability that the sample mean is between 120 and 121.8. 4. Theatre has

Computing Probabilities for Ground Coffee Amounts Spent

In a recent year, about two-thirds of U.S. households purchased ground coffee. Consider the annual ground coffee expenditures for households purchasing ground coffee, assuming that these expenditures are approximately normally distributed as a normal random variable with a mean of $45.16 and a standard deviation of $10.00. 1.

Acceptance-rejection sampling on unit disc

Suppose that the random variables X and Y are independent and uniform on the interval [-1, 1]. You form a random variable Z by sampling from X and Y and computing X^2 + Y^2. Whenever X^2 + Y^2 > 1 the sample is rejected, otherwise it is accepted. Prove that Z is uniformly distributed on [0, 1].

Standard deviation of probability distribution for temperature

Suppose the probability distribution for the high temp in Nevada on June 1 is normally distributed with a mean of 65 degrees. If a box plot was made it would have an IQR = 20 degrees. 1. What's the standard deviation of that probability distribution? I know the answer is 20 / 1.35 - where do you come up with the 1.35?

Probabilty that none watched any of the three sports last year

A survey of a group's viewing habits over the last year revealed the following information: 1. 28% watched gymnastics 2. 29% watched baseball 3. 19% watched soccer 4. 14% watched gymnastics and baseball 5. 12% watched baseball and soccer 6. 10% watched gymnastics and soccer 7. 8% watched all three sports Calcula

Statistics: Problems and Solutions

1.FREQUENCY DISTRIBUTION & DESCRIPTIVE STATISTICS: Open the CUMBA.xls file, which contains data from a random sample of 100 employees at Mock Company Inc. Create a Frequency Distribution of the YEARS OF EXPERIENCE for the employees using intervals of 0-4, 4-8, 8-12, 12-16 and 16-20. Also create the Descriptive Statistics for

Formatting a Report into an Email

See attached data file. Compose an email to the head of the American Intellectual Union which discusses the following: Begin your email to AIU by first providing an overview of the database, i.e. a story about the characteristics which may include the types of variables included, etc. Be sure to include information ab

Binomial distribution and probability of Bill selling three more cars this month

Bill must sell three more cars this month to meet his quota. Tonigh he has after-dinner appointments with five prospective customers, each of whom happens to be interested in a different car. If he has a %30 chance of success with each customer, what is the probability that he'll meet his quota by tomorrow morning? Suppose that

Compute Probabilities: Airline Passengers Arrive in Several Time Periods

Airline passengers arrive randomly and independently at the passenger-screening facility at a major international airport. The mean arrival rate is 10 passengers per minute. Compute the probability of no arrivals in a 1 minute period. Compute the probability that 3 or fewer passengers arrive in a 1 minute period. Compute t

Solving a Binomial Distribution Problem

Bill must sell three more cars this month to meet his quota. Tonight he has after-dinner appointments with five prospective customers, each of whom happens to be interested in a different car. If he has a %30 chance of success with each customer, what is the probability that he'll meet his quota by tomorrow morning? Suppose that