Read the following case study. Then, use the information to answer the accompanying follow-up question. What changes could be suggested to make this test better? Dr. Zak developed a test to measure depression. He sampled 100 university students to take his five item test. The group of students was comprised of 30 men and 70
A plumbing supplier's mean monthly demand for vinyl washers is 24,212 with a standard deviation of 6,053. The mean monthly demand for steam boilers is 6.8 with a standard deviation of 1.7. Compare the dispersion of these distributions. Which demand pattern has more relative variation? Explain.
A set of final examination grades in an introductory quantitative analysis course is normally distributed, with a mean of 73 and a standard deviation of 8. a) What is the probability of getting a grade below 91 on this exam? b) What is the probability that a student scored between 65 and 89? c) The probability is
According to the U.S. Bureau of census current Construction TReport, the average price of a new mobile home in the western part of the United States during 1993 was $40,500. Assume the standard deviation was $8,500/ Should a mobile home selling for $75,000 be considered and outlier? Explain why or why not.
The grade point average of the students at BLK is 2.80 with a standard deviation of 0.84. The grade point average of students at SJK is 2.4 with a standard deviation of 0.84. Which university shows a more relative dispersed grade distribution? Explain why?
Piggy Bank would like to examine the required sample size needed to be able to estimate the mean dollars that each card holder will spend each month. It would like to be within plus or minus $10 of the true mean with a 98% confidence level. The standard deviation is thought to be $500. How many card holders should be sampled? Af
An automobile manufacturer has a new model that they claim gets 27 miles per gallon. A consumer testing agency selects 50 of these cars and finds that the sample mean is 25 miles per gallon and the sample standard deviation (s) is 3 miles per gallon. Using a = 0.05 test the manufacturer's claim.
Using an excel spreadsheet and the stdav function calculate the following data and answer the following questions nunderneath The data I choose to observe was how long I spent doing dishes over a 10-day period. Friday, day 1 - 12 minutes. Saturday, day 2 - 19 minutes. Sunday, day 3 - 22 minutes. Monday, day 4 - 0. Tu
According to Salary Wizard, the average base salary for a brand manager in Houston, Texas is $88,592 and the average base salary for a brand manager is Los Angeles, California, is $97,417. assume salaries are approximately normally distributed, that the standard deviation for brand managers in Houston is $19,900, and that the
The number of homicides in Vermont from 1992 through 2001 is given in the following table. Year Homicide Victims 1992 21 1993 15 1994 5 1995 13 1996 11 1997 9 1998 12 1999 17 2000 12 2001 11 b. Find the standard deviation of the data. c. What percent of the data is within 1 standard deviation of the mean?
You have been offered a position as General Manager of a television manufacturing facility by XYZ Corporation. You have a choice of Plant A or Plant B. At the present time both plants are satisfying their demand for a particular TV (Model FX32) by providing 3200 sets per day on the average. -However, Plant A has a standard
Please help with the following problem. A) When does the t-statistic approximate the z-statistic? Please ask yourself this question before answering: for a probability level of 0.975 on a one-tailed probability distribution, what is z-score and what is t-statistic? Then ask yourself, when does the t-statistic approximates
1) Scenario Analysis. The common stock of Leaning Tower of Pita, Inc., a restaurant chain, will generate the following payoffs to investors next year: Dividend Stock Price Boom $5 $195 Normal economy
According to the data from the College Entrance Examination Board, scores on the SAT-I test have a mean of 1017, and Q1 is 880. The scores have a distribution that is approximately normal. Find the standard deviation, then use that result to find P99.
Juan Salvador just completed a study of the life expectancy of 100 light bulbs and discovered that the mean time that they lasted before burning out was 1,900 hours. If the standard deviation was 150 hours, the empirical rule allows Juan to conclude that approximately 68 of the bulbs burned out between _________ and _________ ho
Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the afternoon shift than on the day shift. A sample of 54 day-shift workers showed that the mean number of units produced was 345, with a standard deviation of 21. A sample of 60 afternoon-shift workers sh
A population of scores has μ = 20 and σ = 5. If every score in the population is multiplied by 2, then the new values for the mean and standard deviation would be: standard deviation = _______________ A sample of scores has M = 30 and s = 10. If 3 points are added to every score in the population, then the n
The weights of items produced by a company are normally distributed with a mean of 4.5 ounces and a standard deviation of 0.3 ounces. a. What is the probability that a randomly selected item from the production will weigh at least 4.14 ounces? Look at attachement too!!! I think I did this all wrong can you help me out
The new Lucky Lady Casino wants to increase revenue by providing buses that can transport gamblers from other cities. Research shows that these gamblers tend to be older, they tend to play slot machines only, and they have losses with a mean of $182 and a standard deviation of $105. The buses carry 35 gamblers per trip. The c
1) The American Automobile Association checks prices of gasoline before many holiday weekends. Listed below are the self-service prices for a sample of 15 retail outlets during Labor Day weekend of 2007 in the Detroit, Michigan area. 3.44 3.42 3.35 3.39 3.49 3.49 3.41 3.46 3.41 3.49 3.45 3.48 3
Please see the attached file for the problem about quality-checking the weight of a manufactured project. Required: i) Using the same price of graph paper, plot a fully - labelled frequency polygon for each operator. ii) Describe what your polygons reveal, making particular reference to: a) The shape of each weight di
Please answer True or False and explain why 1. For a normally distributed population of heights of 10,000 women, µ= 63 inches and ó = 5 inches. The number of heights in the population that fall between 66 and 68 inches is 1156. 2. In a normal distribution, approximately 91.31% of the area under the curve is found to
1.What does it mean for a sample to have a standard deviation of zero? Describe the scores in such a sample. 2. A population has mean, M =100 and standard deviation, s = 20. If you select a single score from this population, on the average, how close would it be to the population mean? Explain answer.
Bank of America's Consumer Spending Survey collected data on annual credit card charges in seven different categories of expenditures: transportation, groceries, dining out, household expenses, home furnishings, apparel, and entertainment ... {See the atached Question File.]
The annual demand for a product is 15,600 units. The weekly demand is 300 units with a standard deviation of 90 units. The cost to place an order is $31.20, and the time from ordering to receipt is four weeks. The annual inventory carrying cost is $0.10 per unit. a. Find the reorder point necessary to provide a 98 percent ser
What is 68-95-99.7 rule? To get a better feel for this concept, give me an example of it from around the home.
Please clarify this statement: If you look at the probability of attaining 6 sigma (2 parts per billion), what does this say when the .400 batting average is at least 6 sigma from the mean?
If the standard deviation of a population is 70 and we want the standard error (the standard deviation of the sample mean) to be 14, what is the number of samples that we need to take?
There is some evidence that, in the years , a simple name change resulted in a short-term increase in the price of certain business firms' stocks (relative to the prices of similar stocks). (See D. Horsky and P. Swyngedouw, "Does it pay to change your company's name? A stock market perspective," Marketing Science v., pp. .)
On the midnight shift, the number of patients with head trauma in an emergency room has the probability distribution shown below. (a) Calculate the mean and standard deviation. (b) Describe the shape of this distribution. x 0 1 2 3 4 5 Total P(x) .05 .30 .25