1. A company has two different processes that make credit cards. Suspecting that machine B has a higher variability than machine A the manager orders a test to be run. The following data was collected: Machine A Machine B Sample size nA= 30 nB=40 Sample Standard Deviation sA= 1.0 sB= 1.7 a. Select the correct hypothesis
Dogs were trained with urine samples from bladder cancer patients and people from a control group who did not have bladder cancer. Results are in the table below. Using a 0.01 significance level, test the claim that the source of the of the sample (healthy or with bladder cancer) is independent of the dog's selections. What do t
When testing for goodness-of-fit with Benford's law, it is necessary to combine categories because not all expected values are at least 5. I don't understand this , use one category with leading digits of 1 , a second category with leading digits of 2,3,4 5 and a third category with leading digits of 6,7,8,9.Are the expected va
Question : Prof. H. Elp Me- John, a mathematics counselor, is interested in the relationship between math anxiety and the successful completion of the introductory college math course. A random sample of 300 college students enrolled in the introductory college math course were given a test to measure their anxiety level on
Question : A quality control engineer wants to compare the production process of parts manufactured by four different companies. The engineer randomly samples a total of 270 parts from the four companies and summarizes the results in the following table. Based upon the results of the sample, can the quality control engineer c
Should Statistics Be a Required Course in College? Yes No Republican 10 26 Democrat 15 17 1. Cell 1,1 (Yes, Republican) Expected Value = 2. Cell 2,2 (No, Democrat) Expected Value = Cell 2,1 (No, Republican) Expected value = Cell 1,2 (Yes, Democrat) Expected value = 3. What is the result of this anal
In a study conducted by Zogby International for the democrat and Chronicle, more than 700 new Yorkers were polled to determine whether the New York state government works. Respondents surveyed were asked question involving pay cuts for state legislators, restrictions on lobbyist, terms limits for legislators, and whether state
This pertains to the topic Nonparametric Methods: Chi-Square Applications: For many years TV executives used the guideline that 30 percent of the audience were watching each of the prime-time networks and 10 percent were watching cable stations on a weekday night. A random sample of 500 viewers in the Tampa-St. Petersburg, F
This pertains to the topic Nonparametric Methods: Chi-Square Applications 1. A study regarding the relationship between age and the amount of pressure sales personnel feel in relation to their jobs revealed the following sample information. At the .01 significance level, is there a relationship between job pressure and age?
Which Treatment is Better? A randomized controlled trial was designed to compare the effectiveness of splinting against surgery in the treatment of carpal tunnel syndrome. Results are given in the table below (based on data from "Splinting vs. Surgery in the Treatment of Carpal Tunnel Syndrome," by Gerritsen et al., Hornal of
The data in the table below are based on data from a Time magazine article. Use a 0.05 significance level to test the claim that whether a subject had low birth weight or normal birth weight is independent of whether the subject graduates from high school by age 19. Do the results show that low birth weight causes people to
Births. Randomly selected births records were obtained and results are listed in the table below (based on data from the National Vital statistics Report, Vol. 49, No.1). Use a 0.05 significance level to test the reasonable claim that births occur with equal frequency on the different days of the week. How might the apparent
Testing a slot machine. The author purchased a slot machine (Bally Model 809), and tested it by playing it 1197 times. When testing the claim that the observed outcomes agree with the expected frequencies, a test statistic of =8.185 was obtained. There are 10 different categories of outcome, including no win, win jackpot, win w
The manager of a computer software company wishes to study the number of hours senior executives spend at their desktop computers by type of industry. The manager selected a sample of five executives from each of three industries. At the .05 significance level, can she conclude there is a difference in the mean number of hours s
Interpretation of results of a chi-square test:"Effects of crude oils on the Gastroinstestinal parasites of two species of Marine fish" For full details of problem, see attached JPG file.
1. Test the null hypothesis that death and location of death are independent variables. 2. For the "over 74" group, estimate the conditional proportion of those who are in acute care, with 90% confidence. (Note: the estimator and its standard error are based on the "sample" consisting just of the "over 74" group.) 3. For t
USA Today reported on preferred types of office communication by different age groups ("Talking Face to Face vs. Group Meetings," USA Today, October 13, 2003, A1). Suppose the results were based on a survey of 500 respondents in each age group. The results are cross-classified in the following table. Type of Communication
This is a question from one of my assignments from a chapter entitled: Nonparametric Methods: Chi-Square Applications. I am trying to figure out how to do this to help me do some of the others. It says we can use: Methods of computation could include the usage of Excel®, SPSS®, Lotus®, SAS®, MINITAB®, or by hand computat
Question: Use the given contingency table to (a) Find the expected frequencies of each cell in the table. (b) Perform a chi-square test for independence. (c) Comment on the relationship between the two variables. Assume the variables are independent. The contingency table shows the results of a random sample of 500 ind
1. In a study of store checkout scanning systems, samples of purchases were used to compare the scanned process to the posted prices. The accompanying table summaries results for a sample of 819 items. Regular-priced items Advertised-special items Undercharge 20 7 Overcharge 15 29 Correct price 384 3
The results from a survey are below: Item Number of Votes Doughnuts 20 Apple Turnovers 6 Doughnut Holes 5 Bismarcks 4 Pomegranate Cookies 5 Based upon all of this information, do a "goodness-of-fit" test to see if the distributions are th
Explain why the value at the bottom left corner on the x axis of the Chi Square distribution curve is zero.
Can right tailed, left tailed, and two tailed distributions be tested with the Chi Square? Explain.
What happens to the shape of the Chi Square distribution curve as the sample size gets larger? What about when the number of cells or groups gets larger?
I need to find out if the percentage distribution differs for smokers and non-smokers between men and women. Use Chi-square (level of significance .05) test and need a 2 by 2 contingency table that looks like: Smokers found Yes No Males 12
There are four entrances to the Government Center Building in downtown Philadelphia. The building maintenance supervisor would like to know if the entrances are equally utilized. To investigate, 500 people were observed entering the building. The number using each entrance is reported below. At the .01 significance level, is the
The safety director of Honda USA took samples at random from the file of minor work related accidents and classified them according to the time the accident took place. Number of Number of Time Accidents Time Accidents 8 up to 9 A.M. 7 1 up to 2 P.M. 9 9 up to 10 A.M. 7 2 up to 3 P.M. 8 10 up to
The chief of security for the Mall of the Dakotas was directed to study the problem of missing goods. He selected a sample of 100 boxes that had been tampered with and ascertained that for 60 of the boxes, the missing pants, shoes, and so on were attributed to shoplifting. For 30 other boxes employees had stolen the goods, and f
In a particular market there are three commercial television stations, each with its own evening news program from 6:00 to 6:30 P.M. According to a report in this morning's local newspaper, a random sample of 150 viewers last night revealed 53 watched the news on WNAE (channel 5), 64 watched on WRRN (channel 11), and 33 on WS
The chief of security for the Mall of the Dakotas was directed to study the problem of missing goods. He selected a sample of 100 boxes that had been tampered with and ascertained that for 60 of the boxes, the missing pants, shoes, and so on were attributed to shoplifting. For 30 other boxes employees had stolen the goods, an