Explore BrainMass

Normal Distribution

Calculations of Probabilities and Normal Distributions

The number of orders that come into a mail-order sales office each month is normally distributed with a mean of 298 and a standard deviation of 15.4. What is the probability that the office receives more than 310 orders in a particular month? 0.782 0.218 0.02

Business problem using statistics

* Please see attachment* i am submitting a complex lengthy stats problem, with accompanying excel file. I am beginning stats student. I am more interested in theoretical explanations to help me to learn the problem. I am also interested in basic level internet references to help me to understand material. It is irrelevant

Normal distribution of incomes

The monthly income of residents of Dayton is normally distributed with a mean of $3000 and a standard deviation of $500. Define the random variable in words. The mayor of Dayton makes $2,250 a month. What percentage of Dayton residents has incomes that are more than the mayor's? Individuals with incomes of less than $1,985

Distribution and Population

1) A distribution has a standard deviation of σ = 8. Find the z- score for each of the following locations in the distribution A) Above the mean by 4 points B) Above the mean by 16 points C) Below the mean by 8 points D) Below the mean by 12 points 2) For the population with µ = 60 and σ = 10 A) Find the z-

Theoretical statistical sampling situation

I need help figuring out a hypothetical situation about 'statistical'sampling. ---------- 1. Identify a situation relating to your work or business interests in which statistical sampling might be (or has been) useful. a. Describe the population and indicate how a sample could be chosen. b. Identify a population par

Probability distribution The length of time it takes from gate to gate for a southwest flight from Phoenix to Atlanta is approximately normally distributed with a mean of 3 hours and a standard deviation of 20 minutes.

1. The length of time it takes from gate to gate for a southwest flight from Phoenix to Atlanta is approximately normally distributed with a mean of 3 hours and a standard deviation of 20 minutes. (Hint - convert all times into minutes) a. What is the probability the trip time will be less than 2 hour and 30 minutes?

Estimates using the Equation of a Least Squares Line

The number of words was noted in each of 100 sentences selected at random from two political thrillers written by different authors; 50 sentences were selected from each book. A summary of the data is given in the table (see attachment). The two-sample z-test is to be used to investigate whether there is a difference, at the

Standard normal distribution: Sketch and find probability

1. Using the standard normal distribution, sketch & find each probability. a. P(0 < z < 2.27) b. P(-1.83 < z < 0) c. P(-1.59 < z < 2.01) d. P(1.33 < z < 1.68) e. P(-2.56 < z < 0.37) f. P(z > 1.66) g. P(z < -2.03) h. P(z > -1.09) i. P(z < 1.93) j. P(z > -1.57)

Normal Distribution of Microwave Time

In a certain microwave oven on the high power setting, the time it takes a randomly chosen kernel of popcorn is normally distributed with a mean of 140 seconds and a standard deviation of 25 seconds. What percentage of the kernels will fail to pop if the popcorn is cooked for (a) 2 minutes? (b) 3 minutes? (c) if you wanted 95

Standard Deviation and Empirical Rule

See attached file. 8. One professor teaches a large section, Section A, of a particular class, and on the first test of the term, the test scores in section A were approximately normally distributed with a mean of 78 and a standard deviation of 6. Another professor also teaches a large section, section B, of the same class, a

Casino Gambling: Random Variables and Probability Distributions

Casino gambling yields over $35 billion in revenue each year in the US. Casino games of pure chance (e.g., craps, roulette, baccarat, and keno) always yield a house advantage. For example in the game of double-zero roulette, the expected casino win percentage is 5.26% on bets made on whether the outcome will be either black or r

Probability, statistics, and loan

See attached Use the following to answer questions 20-22: A $152,400 loan is taken out at 11.5% for 25 years, for the purchase of a house. The loan requires monthly payments. 20. Find the amount of each payment. 21. Determine the total amount repaid over the life of the loan. 22. Find the total interest pai

Normal distribution of women-owned businesses

The following tables provide information about the top women-owned businessesin the U.S. The first table gives year 2000 revenue in millions of dollars and number of employees for Pennsylvania women-owned companies with year 2000 revenues of $70 million or higher. The second table gives the same information for Michigan women-ow

Sampling distribution of proportions

The president of Doerman Distributors, Inc., believes that 34% of the firm's orders come from first-time customers. A simple random sample of 120 orders will be used to estimate the proportion of first-time customers a. What is the probability that the sample proportion will be between .25 and .35 (to 4 decimals)? Time/CNN

Student's t and Standard Normal Comparison

1. Chapter 8: (a) Chapter Review question # 10 (0.5 point) List differences and similarities between the Student's t and the standard normal distribution and carefully show all steps in your response. (b) Chapter Review question # 11 (0.5 point) By means of an example, show that for a given confidence le

Selection of a tail test impact

1) How might the selection of a given -tail test impact the Type I or II error, if any? 2) If the problem itself is not yet stated how might a researcher know which type of -tail test to use? 3) Might there be instances where a test is looking for a section of the area under the curve and not just the extreme ends?

A Manufacturer's Production Policy

The manufacturer of a particular bicycle model has the following costs associated with the management of the product's inventory. In particular, the company currently maintains an inventory of 1000 units of this bicycle model at the beginning of each year. If X units are demanded each year and X is less than 1000, the excess sup

Normal Distribution

Which of the following about the normal distribution is not true? a. About 2/3 of the observations fall within ±1 standard deviation from the mean. b. Its parameters are the mean, &#956;, and standard deviation, &#963;. c. It is a discrete probability distribution. d. Theoretically, the mean, median, and mode are the same

Normal distributions

Part A: Describe the properties of a normal distribution. Explain why there are an infinite number of normal distributions. How does a standard normal distribution differ from any from any other normal distribution, and how is it similar? Explain. Part B: What is the transformation to standardize a normal random variable? Why

Normal distribution

The amounts of money being requested in applications for home loans in Down River Federal Savings follow the normal Distribution with half of $ 70,000 and a standard deviation of $ 20,000.This morning he received a loan application. What is the likelihood: a)that the amount requested is $ 80,000 or more. b)that the amount requ

Normal distribution applied to baseball

5. In baseball, a "no-hitter" is a regulation 9-inning game in which the pitcher yields no hits to the opposing batters. Chance (Summer, 1994) reported on a study of no-hitters in Major League Baseball (MLB). The initial analysis focused on the total number of hits yielded per game per team for all 9-inning MLB games played betw

Normal Distribution Characteristics

1. True or False? Replacement is allowed in binomial experiments. Explain your answer. 2. True or False? Two normal distributions that have the same standard deviation have the same shape, regardless of the relationship between their means. Explain your answer.

Statistics Study Guide 2

1. Which of the following statement(s) about the normal probability distribution is/are true? a. The mean equals the mode and the median b. The median equals the mode c. The mean divides the distribution into two equal parts d. All of the above e. None of the above 2. a. 375 and 425 b. 300 and 500 c. 390 and 410