A company implemented a safety program designed to reduce the number of work related injuries. Human Resources department collected the following data to verify the effectiveness of the program: Number of injuries per week Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 Week 8 Before 4 5 2 2
A recent article in the Wall Street Journal reported that the 30-year mortgage rate is now less than 6 percent. A sample of eight small banks in the Midwest revealed the following 30-year rates (in percent): 4.8, 5.3, 6.5, 4.8, 6.1, 5.8, 6.2, 5.6 At the .01 significance level, can we conclude that the 30-year mortgage rat
You have collected the following data from two suppliers. Are the suppliers significantly different at the 0.05 level of significance? Supplier One Supplier Two Sample Size 45 52 Sample mean 8.1 9.3 Sa
6. The following data was collected on the thickness of glass being manufactured. The glass thickness is normally distributed. 0.262 0.256 0.263 0.223 0.251 0.238 0.184 0.248 0.189 0.204 0.217 0.255 0.240 0.197 0.237 0.265 0.275 0.236 0.225 0.234 0.261 0.296 a. If the manufacturer claimed that the glass was 0.250 inches thi
Arnold Palmer and Tiger Woods are two of the best golfers to ever play the game. The question was raised as to how these two golfers would have compared if both were playing at the top of their game. The following sample data show the results of 18-hole scores during a PGA tournament competition. Palmer's scores are from
One sample t test, Independent sample t test, Z test for population proportion . See attached file for full problem description.
Using AIU's large database of survey responses from the AIU data set, complete the following: Perform hypothesis testing on one variable's data. (Choose either the intrinsic or extrinsic column.) Perform a t-test by formulating a null and an alternative statement, choosing an acceptable significance value, selecting the test s
Comparison of mean tread wear of two brands of car by paired students t test.
Question : A double blind study was carried out to determine whether a certain calcium supplement reduces systolic blood pressure in adult black males. One group of 16 took the calcium supplement and a control group of 14 received a placebo. The summary statistics for the decrease in blood pressure were as follows: Group
Students in General Psychology were allowed to sign up for one of two sections of that course. One section has a virtual lab component to it, in which they are given additional assignments to supplement the lecture content. These exercises consist of various games, demonstrations etc., that the students complete utilizing the CD
The management of Discount Furniture, a chain of discount furniture stores in the Northeast, designed an incentive plan for salespeople. To evaluate this innovative plan, 5 salespeople were selected at random, and their weekly incomes before and after were recorded. Salesperson Before After Sid Mahone $320 $340 Carol Qui
Compare and contrast a Difference of Means test with a Paired Difference test. What, fundamentally, are we testing for in each? When do you use the difference of means? When do you use the paired difference? Explain why in both instances.
1) We wish to estimate the average daily yield of a chemical manufactured in a chemical plant. The mean daily yield was recorded for 50 days, and found to be 871 tons/day. The standard deviation turned out to be 21 tons. Test the null hypothesis that the average daily yield of the chemical is 880 tons at . 2) Given the
Two boats, the Prada and the Oracle are competing for a spot in the upcoming America's Cup race. They race over a part of the course several times. Below are the samples times in minutes. At the .05 significance level, can we conclude that there is a difference in their mean times? Prada: 12.9 12.5 11.0 13.3 11.2 11.4 11.6 1
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
6. Create a dependent variable by computing a difference score between the pretest and post-test achievement scores. 7. Conduct an independent samples t test to evaluate the effectiveness of integration on academic achievement. 8. What did the Levene's test evaluate? 9. Which t ratio is the appropriate result? Why?
Question : In comparing purchases from 2 companies, a sample of 16 purchases from Cambells with the mean $ 11, 045 and Standard Deviation of $ 835 is taken. For a sample of 18 purchases from Rainer mean cost is $ 12,840 and Standard Deviation is $ 1545. At the 5% significance level, can we conclude that the cost from Rainer
T test to evaluate one set of data points with another set of data points (Use t test testing to evaluate which set of data points (population) will have a larger mean difference). I need help with evaluating the information and stating the hypotheses and the final decision (to reject or fail to reject H0). Some of the informati
Question: A claim is made that the mean height of police officers is 5feet 11inches. To test whether this claim is true or not, a random sample of 25 police officers was gathered. This sample had a mean height of 5 feet 10inches with s=3inches. Test at the 5% significance level
Question The average IQ of a group of researchers is quoted to be 260. Thinking that this figure is too large, consulting firm tested a random sample of 8 researchers and found that the average IQ was 250 with s=8. Test at a level of significance of 1%.
Question It is claimed that a large corporation discriminates against its women employees in its promotion practices. Over many years, the mean time before first promotion for its male employees has been 3 years. A random sample of 20 females who had worked there many years showed a mean time of 3.8 years before its first pro
1. A real estate agent gathered data from homes that recently sold in two local neighborhoods. It was decided to test to determine the relationship of the mean land values from the two neighborhoods. The following printout was generated using the individual sample variances as estimates of the unknown population variances. H
A. A study examines self-esteem and depression in children. A sample of 25 children with low self- esteem is given a standardized test for depression. The average score for the group is M = 93.3. For the general population, scores on the depression test form a normal distribution with a mean of Mu = 90 and a standard deviat
A study of n = 46 hospital employees who were diagnosed with a latex allergy from exposure to the powder on latex gloves. The number of latex gloves used per week by the sampled workers is summarized as follows: xbar = 19.3 and s= 11.9. Let μ represent the mean number of latex gloves used per week by hospital employees.
The MacBurger restaurant chain claims that the waiting time of customers for service is normally distributed, with a mean of 3 minutes and a standard deviation of 1 minute. The quality-assurance department found in a sample of 50 customers at the Warren Road MacBurger that the mean waiting time was 2.75 minutes. At the .05 sign
The management of White Industries is considering a new method of assembling its golf cart. The present method requires 42.3 minutes, on the average, to assemble a cart. The mean assembly time for a random sample of 24 carts, using the new method, was 40.6 minutes, and the standard deviation of the sample was 2.7 minutes. Using
Students t test for difference in turnover rates in two stocks. See attached file for full problem description.
The assignment starts out by stating, you are given the responsibility fo presenting the results of a yearlong study of a teaching strategy to the school board. Fifty-two students were chosen at random from the school population to participate in the study. Twenty-six students were then randomly chosen to serve as a control gr
1. You want to test the effectiveness of a new diabetes management program on lowering fasting blood sugar (glucose) levels for individuals who have diabetes. Background: According to information found on the internet, the following are glucose level ranges and their associated meaning: Glucose Level (mg/dL) Test Resu
For this exercise, let's assume that you are setting up this study, rather than being called in after the fact. A review of the clinic's records indicates that their 8-week diet produces an average weight loss of 3.1 kg, with a standard deviation of  2.4 kg. If we desire to measure a large effect (Cohen's d  0.8)