A class survey in a large class for first year college students asked "About how many minutes do you study on a typical weeknight?" The mean response of the 269 students was x (bar over x) = 137 minutes. Suppose that we know that the study time follows a Normal distribution with standard deviation = 65 minutes in the populatio
Successful hotel managers must have personality characteristics often thought of as feminine as well as those often thought of as masculine. The Bem Sex-Role Inventory (BSRI) is a personality test that gives separate ratings for female and male stereotypes, both on a scale of 1 to 7. A sample of 148 male general managers of th
See attached data file. Predicting runs scored in baseball. Statistician Scott Berry built a multiple regression model for predicting total number of runs scored by a Major League Baseball team during a season. Using data on all teams over a 9-year period (a sample of n = 234), the results in the attached table were obtai
Describe whether this statement regarding statistical significance are true or false. When your results are found to be statistically significant, can one conclude that they will have a meaningful effect in the clinic. The researcher can determine the level of statistical significance (if so how).
Chicken Delight claims that 86 percent of its orders are delivered within 10 minutes of the time the order is placed. A sample of 80 orders revealed that 81 percent were delivered within the promised time. At the .10 significance level, can we conclude that less than 86 percent of the orders are delivered in less than 10 minutes
According to a study by the American Pet Food Dealers Association, 42 percent of U.S. households own pets. A report is being prepared for an editorial in the San Francisco Chronicle. As a part of the editorial a random sample of 265 households showed 175 own pets. Does this data disagree with the Pet Food Dealers Association dat
A researcher claims that the average age of people who buy lottery tickets is 61. A sample of 30 is selected and their ages are recorded as shown below. The standard deviation is 9. At a = 0.05 is there enough evidence to reject the researcher's claim? Show all work. 65 63 75 52 22 80 72 56 82 56 24
Please help with the following questions. What is a one tail test? A two tail test? When are they used? What is a type I error? A type II error? In the hypotheses: Ho: A new auto engine gets the same mpg as an older version Ha: A new auto engine gets more mpg than an older version
What does "level of proof" mean? (Alpha in hypothesis testing.) What is the technical definition of alpha? When might a "high level of proof" be required in business? Why does a "high level of proof" mean a small value of alpha?
See attached file. Using the attached Excel numerical data, perform a linear regression analysis and hypothesis test on the data. Include raw data tables and the results of computations, using both graphical and tabular methods of displaying data and results. Please include written detail of the hypothesis test. Hypothesi
Suppose you are testing the differences in attitudes toward health care reform using Democrats, Republications, and Independents. What statistical test would you use?
Suppose the manager of a pet store wants to determine if there is a difference in the amount of money spent in the store, on average, by owners of dogs vs. owners of cats. Consider dog owners as group 1 and cat owners as group 2. Assume that the population standard deviations are equivalent between groups. Below are the sampl
1. The following data are from an independent-measures experiment comparing two treatment conditions. Do these data indicate a significant difference between the treatments Treatment one: 13 9 7 11 Treatment two: 9 5 5 9 2. A sample of freshmen takes a reading comprehension test and their scores are summarized b
FLOWER PRODUCTION OF DWARF SCHRUBS Dwarf shrubs are popular with model home landscapers. Stetson University researchers conducted an experiement to determine the effects of fire on the schrub's growth. Twelve experimental plots of land were selected in a pasture where the shrub is abundant. Within each plot, three dwarf sh
Faced with rising fax costs, a firm issued a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 35 randomly chosen fax transmissions during the next year, yielding a sample mean of 14.44 with a standard devi
A Washington Post-ABC News poll found that 72% of people are concerned about the possibility that their personal records could be stolen over the Internet. If a random sample of 300 college students at a Midwestern university were taken and 228 of them were concerned about the possibility that their personal records could be sto
Why is statistical significance not necessarily of practical important difference to a business decision? Provide an example and explain. Why do statisticians play only a limited role in deciding whether statistical significance requires a business action?
In the 1990s, Massachusetts introduced the mandatory student testing program Massachusetts Comprehensive Assessment System (MCAS). According to the Massachusetts Department of Education, "based on 1998 MCAS test scores, all schools were placed in one of six baseline categories, Very High, High, Moderate, Low, Very Low or Critica
1. A machine is set produce tennis balls so the mean bounce is 36 inches when the ball is dropped from a platform of a certain height. The productions supervisor suspects that the mean bounce has changed and is less than 36 inches. As an experiment a sample of 12 balls was dropped from the platform and the mean height of the bou
1. The mean construction time for a standard two-car garage by Arrowhead Construction Company is 3.5 days. The time for the construction process follows the normal distribution. The construction process is modified through the use of 'precut and assembled roof trusses' rather than onsite construction of roof rafters. This should
3. You obtain the following regression statistics for the relationship between defect and volume at one of your plants. You have a random sample of results from 160 shifts at the plant. Model Summary Model R R Square Adjusted R Square Std. Error of the Estimated 1 .740 .548 .545
Salaries of postgraduates Refer to "Economics of Education Review" (Vol. 21, 2002) study of the relationship between education level and earnings, Excercise 6.31 (p. 336). A National Adult Literay Survey revealed that males with a postgraduate degree had a sample mean salary of of $61,340 (with standard error = $2,185), whil
See data file attached. Using AIU's survey responses from the AIU data set,complete the following requirements in the form of a report: Perform a two-tailed hypothesis test on both the intrinsic and the extrinsic variable's data, using a .05 significance level. Begin by creating a null and an alternate statement. Us
See the attached file for clarity in the tables. 1. It is suspected that high pollution levels (measured by number of particulates found in the air) increase the levels of asthma attacks. A researcher collects data on50 people who experienced an asthma attack during the course of one year. For each person the number of part
See attached data file. Using AIU's survey responses from the AIU data set, complete the following requirements in the form of a report: 1. Perform a two-tailed hypothesis test on both the intrinsic and the extrinsic variable's data, using a .05 significance level. 2. Begin by creating a null and an alternate statement.
The following are average weekly inventory costs in thousands of dollars for two proposed inventory control policies. The values were obtained from independent replications of a simulation model of the system. Test the hypothesis that the average weekly cost for policy A is less than that of policy B at a 5% significant level.
See attached file for data. What are the effects of gender and worksite location (on- or off-site) on level of confidence? In other words: a. Is there a gender difference in confidence? b. Does type of worksite experience affect confidence? c. Is there an interaction between gender and worksite in their effect on confide
A purchasing manager for a large university is investigating which brand of LCD projector to purchase to equip "smart" classrooms. Of major concern is the longevity of the light bulbs used in the projectors. The purchasing manager has narrowed down the choice of projector to two brands, Infocus and Proxima, and wishes to determi
As part of your work for an environmental awareness group, you want to test the claim that the mean waste generated by adults in the country is more than three pounds per person per day. In a random sample of 11 adults in the country, you find that the mean waste generated per person per day is 3.3 pounds and the standard deviat
Do students at various universities differ in how sociable they are? Twenty-five students were randomly selected from each of three universities in a region and were asked to report on the amount of time they spent socializing each day with other students. The result for University X was a mean of 5 hours and an estimated po