Whirling disease is a deadly disease that affects trout in Montana riversIn a follow-up to a 2006 study conducted by the Montana Department of FishWildlife and Parks (FWP)researchers sought to determine if the proportion of trout afflicted by whirling disease in the Gallatin river differs between rainbow trout and brown trout. To test this theory, researchers collected a representative sample of 527 rainbow trout and 459 brown trout. Of the 527 rainbow trout collected, 120 had developed whirling disease; of the 459 brown trout collected, 74 had developed whirling disease Calculate the relative risk of whirling disease for rainbow trout compared to brown trout in this sample.

Crime incidents by quarantine violators. On June 10, 2020, CNN Philippines reported that the Philippine National Police (PNP) said that incidents of crime had decreased sharply during the country’s community quarantine, which lasted for 84 days. Concurrently, the Joint Task Force COVID Shield reported that a total of 193,779 quarantine violators had been warned, fined, or arrested. About 65.05% of them were from Luzon. Consider a random sample of 500 quarantine violators. a. Compute m and s for the random variable x, the num- ber of quarantine violators who are from Luzon. b. From the sample of 500 quarantine violators, is it likely that less than half are not from Luzon? Explain.

For several decades, it was a common practice in Southern California for houses to be built with pools in the backyard (as any airplane flight which ends at a Southern California airport will reveal). Now, however, that practice may be changing, possibly because of the recent demand for landscaped homes, which experts believe help reduce pollution. A recent study examined a random sample of  167  houses built in Southern California between 1950 and 1985 and an independent, random sample of  80  houses built in Southern California from 1992 to the present. The sample of houses built in 1950-1985 contained  71  houses with pools, and the sample of houses built from 1992-present contained  31  houses with pools. Based on this survey, can we conclude, at the  0.05  level of significance, that the proportion  p1  of all Southern California houses built in 1950-1985 that were built with pools is greater than the proportion  p2  of all Southern California houses built from…

Your statistics instructor often ponders the relationship between commute time and job satisfaction while driving back and forth to campus.  Your instructor hypothesizes that people with a shorter commute time will have higher degrees of job satisfaction.  Randomly sampling 600 Valley commuters, the instructor finds the following data listed in frequencies: Table 2: Commuters by Length of Commute and Job Satisfaction Job Satisfaction Number Who Commute 20 Minutes or Less Number Who Commute 21 to 40 Minutes Number Who Commute 41 Minutes or More Total Number for Each Level of Job Satisfaction Dissatisfied 10 60 140 210 Neutral 45 59 51 155 Satisfied 145 60 30 235 Total Number for Each Commute Time Range 200 179 221           1. Change frequencies to column percentages.

The National Association of Home Builders provided data on the cost of the most popular home remodeling projects. Sample data on cost in thousands of dollars for two types of remodeling projects are as follows. Excel File: data 10-41.xlsx Kitchen 25.2 17.4 22.8 21.9 19.7 Master Bedroom 18.0 22.9 26.4 24.8 26.9 Kitchen 23.0 19.7 16.9 21.8 23.6 Master Bedroom 17.8 24.6 21.0 a. Develop a point estimate of the difference between the population mean remodeling costs of kitchens and master bedrooms. (Enter negative values as negative numbers. Report in thousands of dollars with no commas in your answer.) Point estimate = $ thousand b. Develop a 90% confidence interval for the difference between the two population means. (to 1 decimal and enter negative values as negative numbers) ) in thousands of dollars.

When an audit must be conducted that involves a tedious examination of a large inventory, the audit may be very costly and time consuming if each item in the inventory must be examined. In such situations, the auditor frequently obtains a random sample of items from the complete inventory and uses the results of an audit of the sampled items to check the validity of the company's financial statement. A large company’s financial statement claims an inventory that averages $600 per item. The following data are the auditor’s assessment of a random sample of 75 items from the company’s inventory. The values resulting from the audit are rounded to the nearest dollar. Estimate the mean value of an item in the inventory using a 95% confidence interval. Is there substantial evidence (a 5 .01) that the mean value of an item in the inventory is less than $600? What is the target population for the above inferences? Would normal distribution–based procedures be appropriate for answering the…

QSR Magazine published the latest results of its annual quick serve resturant drive-thru study. One aspect of the study examined the customer drive-thru wait times for various brands. The drive-thru wait times for random samples of customers at Chick-fil-A, McDonald's, and KFC are given in the table below. Brand                                            Customers drive-thru wait times (in seconds) Chick-fil-A                                     485     496     489    460     487    477   495 McDonald's                                   356     362     343    327   369    351     350 KFC                                                291    269      251    283   286    294    278   (a) Conduct a hypothesis test using a=0.05 to determine whether the mean drive-thru wait times of customers at Chick-fila-A, and KFC are the same. Assume that drive thru wait times for each of these brands reasonably follow a normal distribution. (b) Use the sample data collected in Problem 4 to construct…

A 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. Using data from a sample of 42 credit card accounts, assume that each account was used to identify the annual credit card charges for groceries (population 1) and the annual credit card charges for dining out (population 2). Using the difference data, with population 1– population 2, the sample mean difference was d = $870, and the sample standard deviation was s,= $1,125. (a) Formulate the null and alternative hype to test for no difference between the population mean credit card charges for groceries and the population mean credit card charges for dining out. 0> Prt :°H 0 = Pri :ºH O O Ho: Hdso H: H=0 (b) Calculate the test statistic. (Round your answer to three decimal places.) What is the p-value? (Round your answer to four decimal places.) Can you conclude that the population…

A district health officer wishes to determine if the six villages in his district are independent of residents contracting malaria, schistosomiasis, cholera or tuberculosis. Identity an appropriate statistical test and the tail of the test for the problem. Assume all samples used for study come from a normal population.

Dental health issues remain a barrier to attendance, as evidenced by a 2010 Los Angeles School Attendance Review Board (SARB), which lists dental health, along with homelessness, in the top barriers to attendance. The Dental Hygiene program at West Los Angeles College collects data on its clinic patients to help instructors and students better understand their patient population. From July 2017 to December 2019 the program treated 3421 patients. Students were asked to analyze a random sample of 127 patients from that time period and found that 36.4% had severe periodontal disease (infections and inflammation of the gums and bone that surround and support the teeth). Identify the population: Identify the sample: Identify the parameter of interest: Identify the statistic: