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    Standard Deviation

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    Gibbs Baby Food company hypothesis testing

    The Gibbs Baby Food Company wishes to compare the weight gain of infants using their brand versus their competitor's. A sample of 40 babies using the Gibbs products revealed a mean weight gain of 7.6 pounds in the first three months after birth. The standard deviation of the sample was 2.3 pounds. A sample of 55 babies using the

    Variance and the standard deviation of the number of University admissions

    The director of admissions at Kinzua University in Nova Scotia estimated the distribution of student admissions for the fall semester on the basis of past experience. What is the expected number of admissions for the fall semester? Compute the variance and the standard deviation of the number of admissions. Admissions

    General Statistics Problem

    A random sample of eight observations from the first population resulted in a standard deviation of 10. A random sample of six observations from the second population resulted in a standard deviation of 7. At the .02 significance level, is there a difference in the variation of the two populations? Ho: variances are equal H1

    Ratio of two population variance

    A manufacturer needs to compare the weights of a product produced at 2 different plants. A random sample of 16 items from Plant A has a standard deviation of 12 milligrams and random sample of 25 items from Plant B has a standard deviation of 15 milligrams. Assuming that both populations are normally distributed, construct a 99%

    Range, Mean, Variance and Standard Deviation

    Find th range, mean, variance, and standard deviation of the sample sata set: 19 20 17 21 21 21 19 18 19 19 17 17 15 18 18 18 18 17 17 17 Range: Sample mean, round to the nearest hundredth Sample variance (use unrounded values to find the answer, round to the nearest hundredth) Sample standard deviatio

    Charting Data for Average Family Income

    An economist wishes to estimate the average family income in a certain population. The population standard deviation is known to be $4,500, and the economist uses a random sample of size = 225. What is the probability that the sample mean will fall within $800 of the population mean?

    Finding the mean of a normal distribution of scores

    A psychologist has designed a questionnaire to measure individuals' aggressiveness. Suppose that the scores on the questionnaire are normally distributed with a standard deviation of 80. Suppose also that exactly 15% of the scores exceed 700. Find the mean of the distribution of scores. Carry your intermediate computations to at

    Guessing Answers (Probability Distributions)

    Several students are unprepared for a multiple-choice quiz with 10 questions, and all of their answers are guesses. Each question has five possible answers, and only one of them is correct. A) Find the mean and standard deviation for the number of correct answers for such students. B) Would it be unusual for a student to pas

    One tail test at 5% level of significance

    A recent national study found that the average high schools student rented 6.3 videos per month. A random sample of 36 college students found that they rented 6.4 per month with a deviation of 0.5. At the 0.05 α, using a 1 tail test can we conclude that the college students watch more videos a month than the high school s

    Maximum Tolerable Error

    I am trying to calculate the maximum tolerable error given a sample size. I am given the standard deviation and I have been told that the mean is within 1 of the population mean. Without the actual mean, how can I calculate the maximum tolerable error? I am using: maximum allowable error = (z-value * standard deviation)/sq

    Stat Class

    #78. Consider a sample x1, x2, ..., xn and suppose that the values of x, s2, and s have been calculated. _ a. Let yi = xi - x for i = 1, ..., n. How do the values of s2 and s for the yi's compare to the corresponding values for the xi's? Explain. _ b. Let zi = (xi - x ) / s

    Find Probabilities, Mean and Standard Deviation, and Distribution

    1. The number of hours needed by students in an economics course to complete a term paper are attached. A student is selected at random. Find the following probabilities. a. the student took more than 9 hours b. the student took less than 6 hours c. the student took between 7 and 9 hours, inclusive. 2. A box holds 5 bl

    Design and Analysis of Experiment

    A product developer is interested in reducing the drying time of a primer paint. Two formulations of the paint are tested: formulation 1 is the standard chemistry, and formulation2 has a new drying ingredient that should reduce drying time. From experience it is known that the standard deviation of drying time is 9 minutes, and

    Standard Score Found

    Find the standard score for the value x=452 realative to its sample, where the sample mean is 500 and the standard deviation is 32. Then find the value of x that corresponds to the standard score of 1.2, where the mean is 135 and the standard deviation is 15.

    Standard deviation with large variance

    Please explain the process to find the standard deviation with a big difference in the numbers...in seconds, 0,250,0,164,0,519. Please show how to find from this data.

    Quality calc

    A new machine has just been installed to cut and rough shape large slugs. The slugs are then transferred to a precision grinder. One of the critical measurements is the outside diameter. The quality control inspector randomly selected 5 slugs each hour, measured the outside diameter and recorded the results. The measurements i

    Control Limits for Quality Managers

    Assume that you are the Quality Manager for the Emerson D. Meritz Machine Tool Company. Your model IE566 grinding machine is afflicted by three types of defects classified as major (type A), serious (type B) and minor (type C). You wish to set up a demerit system for this product using the following weighting scheme: D=100

    Standard Deviation.

    The College Board American College Testing Program reported a population mean SAT score of  =1017. Assume that the population standard deviation is  = 100. a. What is the probability that a random sample of 75 students will provide a sample mean SAT score within 10 of the population mean? b. What is the pr

    Standard deviation

    A manufacturing process produces units that average 10 inches in length with a standard deviation of 3.2 inches. If only those units between 9.5 and 10.5 inches can be used, how many out of a sample of 100 must be thrown away?

    Unique Distribution

    If a balanced die is rolled six times and the outcomes create a unique distribution, perform the following: P(exactly three fives) {Use formula} mean {Use formula} variance {use formula} standard deviation {use formula} Problem # 2 If 20%

    Business forecasting

    Dick Hoover, owner of Modern Office Equipment, is concerned about freight costs and clerical costs incurred on small orders. In an effort to reduce expenditures in this area, he has decided to introduce a discount policy rewarding orders over $40 in the hope that this will cause customers to consolidate a number of small orders

    Calculating midrange, first quartile, mean, standard deviation

    Sixteen retail outlets were surveyed to find the cost of a window chiller. The results are 280,310,265,298,285,325,360,340,260,275,295,280,355,295 and 355. find the midrange find the value corresponding to P50 find the first quartile (in dollars) find the mean find the unbiased standard deviation what is th z-score,

    Sample size necessary to estimate a population mean with a sample mean.

    A personality test has a subsection designed to assess the "honesty" of the test-taker. Suppose that you're interested in the mean score on this subsection among the general population. You decide that you'll use the mean of a random sample of scores on this subsection to estimate the population mean. What is the minimum sample

    Anita's, a fast-food chain specializing in hot dogs and garlic fries

    Anita's, a fast-food chain specializing in hot dogs and garlic fries, keeps track of the proportion of its customers who decide to eat in the restaurant (as opposed to ordering the food "to go") so it can make decisions regarding the possible construction of in-store play areas, the attendance of its mascot Sammy at the franchis

    A machine that manufactures automobile pistons...

    Please see the attached file for full problem description. --- A machine that manufactures automobile pistons is estimated to produce a defective piston of the time. Suppose that this estimate is correct and that a random sample of pistons produced by this machine is taken. a. Estimate the number of pistons in the samp

    Find Standard Deviation using the computational formula

    "My Bank" opens a branchin a commercial district. The bank wants to find out the waiting time of their customers during the Friday evening hours from 5pm to 8pm. Accordingly, the waiting time is recorded for all customers during these hours over a month. A random sample of 20 customers is selected; the waiting time, in minutes,

    Comparing the Average Difference and Standard Deviation Between Two Populations

    While it cannot be denied that advertising impacts sales, it is also true that advertising is expensive and companies want to advertise in ways that have the greatest benefit for the amount of money spent. A company that sells snack food designs two different advertising strategies, one focusing on print media and the other on r