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    Normal Distribution

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    Normal distribution and Hypothesis Testing

    Problem:1 Suppose that x is normally distributed random variable with µ = 11 and variance = 4. Find each of the following: a)P(10<x <12) b)P(x > 13.24) c)P(x < x0) 0.75 find Xo Problem:2.Consider the following hypothesis test. Ho: µ >; 10 Ha: µ < 10 A sample with n = 50 provides a sample mean of 9.46 and samp

    Probability using Normal Distribution

    Using the normal distribution, answer the following questions. 1. A pharmaceutical drug has mean effective duration of 10.4 hours with a standard deviation of two hours. In what percentage of the patients will the effectiveness of the drug be: a) Greater than 13 hours? b) At least 9 hours? c) Between 11.8 and 14.6 hour

    Bell Curve Chart: The Number of Men Needed

    Create a bell curve chart that shows the number of men needed per day for a 10,000 man hour job. The start date is 1/1/2008 and the end date is 6/1/2008. The job will run for a total of 21.71 weeks and there will be 108.57 work days. The estimated man hours is 10,000 and each worker will work an 8 hour shift 5 days out of the we

    Statistics - Standard Deviation Normal Distribution

    A paint manufacturer has a normal distribution of 100,000 gallons per day of production with a standard deviation of 10,000 gallons. Management wants to create an incentive bonus when production exceeds the 90th percentile of the distribution. At what level should management pay the incentive bonus?

    Probability and Probability Distribution

    1. customers in a bank A bank has a drive thru service. The number of customers arriving during a 15 minute period is distributed as shown. Find the mean, variance, and standard deviation for the distribution Number of customers X 0 1 2 3 4 Probability

    Statistics - Normsdist and Tdist

    Here are tables of the Standard Normal and Student's t distributions. The formulas for the first value in each P column are, respectively =NORMSDIST(A3) and =TDIST(C3,20,2), where column A is the one labeled "Z" and column C is labeled "t". "t". 1. What is the meaning of the number given in the P column under NORMSDIST? 2)

    Normal Distribution: Length of a Typical Baseball Game

    Assume that the length of a typical televised baseball game, including all the TV timeouts, is normally distributed with a mean of 2.45 hours and standard deviation of 0.37 hour. Consider a televised baseball game that begins at 2:00 in the afternoon. The next scheduled program broadcast starts at 5:00. a. What is the probabi

    Ages of New Mothers - Normal Distribution

    The ages of all new mothers have a mean of 30.0 years and a standard deviation of 3.0 years. Provide answers correct to one decimal place below. Assuming that the data is normally distributed, the percentage of new mothers aged less than 24.5 years is ___% in the population.

    Mensa - Normal Distribution

    To become a member of Mensa, one has to pass the qualifying exam. If the scores on the exam are normally distributed with a mean of 80 and a standard deviation of 25, and if only the top 20% of the people taking the exam are admitted, what is the passing score?

    Normality and business research

    1. R.C. Geary wrote some 70 years ago that "Normality is a myth. There never was, is, nor will there ever be a Normal distribution". What do you think he meant and what relevance does it have to your work?(Read the Week 2 Lecture 1 before answering) 2.How do you feel that the inferential statistical technique of Hypothesis Te

    Normal approximation to the bionomial distribution

    11% of all books sold are romance genre. If the bookstore sells 316 books on a given day, what is the probability that fewer than 40 are romances, at least 25 are romances, between 25 and 40 are romances? What is n?p?q? Are both np and nq larger than 5? Why is this important to consider?

    Statistics - Normal Distribution for Z Scores

    Assuming that x has a normal distribution, find the indicated probability a) p(40<_x<_47) mean=50, stand.dev.=15 and p(x_>2)mean=3stand.dev.=0.25 b) Find z value and sketch the are described 1) 97.5%of normal curve lies to the left of z 2) Find z such that 95% of standard normal curve lies to the right of z

    How much should a healthy kitten weigh?

    How much should a healthy kitten weigh? A healthy 10-week-old (domestic) kitten should weigh an average of mu = 23.5 oz with 95% of data ranging from 13 to 34 oz. Let x be a random variable that represents the weight (in ounces) of a healthy 10-week-old kitten. Assume that x has a distribution that is approximately normal. m

    Normal Distribution and Z-Scores

    1. For each of the following z-scores, sketch a normal distribution and draw a vertical line at the location of the z-score. Then, determine whether the tail is to the right or the left of the line and find the proportion in the tail. a. z = 2.00 b. z = 0.50 c. z = -1.00 d. z = -0.75. 2. The distribution of score

    French Fries - Normal Distribution

    The lengths of 45 French fries, randomly selected from a huge shipment, were measured and a mean length of 8.4 cm with standard deviation of 3.1 cm was found. a. Construct a 95% confidence interval for the population mean length of a French fry. b. Calculate the number of French fries that would have to be sampled and measur

    Grading Egg Sizes - Normal Distribution

    In grading eggs into small, medium and large, Margi farms packs the eggs that weigh more than 4.25 ounces in packages marked " large" and the eggs that weigh less than 2.45 ounces in packages marked " small" the remainder are packed in packages marked " medium". If a day's packaging contained 10.56% large and 4.01% small eggs, c

    Income Tax Refunds - Normal Distribution

    According to the IRS, income tax returns one year averaged $1332 in refunds for taxpayers. One explanation of this figure is that taxpayers would rather have the government keep back too much money during the year than to owe it money at the end of the year. Suppose the average amount of tax at the end of a year is a refund of $

    Cable Companies - Normal Distribution

    According to the Yankee group, 53% of all cable households rate cable companies as good or excellent in quality transmission. Sixty percent of all cable households rate cable companies as good or excellent in having professional personnel. Suppose 300 cable households are randomly contacted? a. What is the probability that m

    Fresh Fruit Consumption - Normal Distribution

    The Statistical Abstract of the United States published by the US Census Bureau reports that the average annual consumption of fresh fruit per person is 99.9 pounds. The standard deviate of fresh fruit consumption is about 30 pounds. Suppose a researcher took a random sample of 38 people and had them keep a record of the fresh f

    Floppy Disks - Normal Distribution

    The Floppy Disk Company makes 3.5" floppy disks for disk drives that are 3.7" wide. The size of the manufactured disk is normally distributed with a standard deviation of 0.1". The company manufactures 1000 disks every hour. a. What percentage of the disks would you expect to be greater than 3.7"? b. In one hour, how man

    A criminologist has developed a test to measure self-control. The test is normed so that it has a mean of 70 and a standard deviation of 20. The scores are normally distributed ...

    A criminologist has developed a test to measure self-control. The test is normed so that it has a mean of 70 and a standard deviation of 20. The scores are normally distributed in the population of college students used to develop the test. a. What is the percentile rank of a score of 40? b What percentage of scores falls be

    A union of restaurant and foodservice workers would like to estimate the mean hourly wage,(m), of foodservice workers in the U.S. The union will choose a random sample of wages and then estimate (m) using the mean of the sample. What is the minimum sample size needed in order for the union to be 99% confident that its estimate is within $0.45 ...

    A union of restaurant and foodservice workers would like to estimate the mean hourly wage,(m), of foodservice workers in the U.S. The union will choose a random sample of wages and then estimate (m) using the mean of the sample. What is the minimum sample size needed in order for the union to be 99% confident that its estimate i

    Combinations and Percentage Probabilities

    5.50 A tax account has three choices for the method of treating one of a client's deductions. After this choice has been made, there are only two choices for how a second deduction can be treated. What is the total number of possibilities for the treatment of the two deductions? 5.51 A committed consists of eight members

    Normal Approximations to the Poisson Distribution

    Suppose the X is a Poisson random variable with lambda = 6. a) Compute the exact probability that X is less than 4 b) Approximate the probability that X is less than 4 and compare to a) c) Approximate the probability that 8<X<12