Anecdotal evidence suggests that anxiety disorder may contribute to the irritable bowel syndrome (IBS), a condition characterized by nausea, alternating constipation and diarrhea, and no identifiable gastrointestinal pathology. Researchers administer an online questionnaire regarding IBS symptoms to 10,000 people who have an established diagnosis of anxiety disorder in the United States, Canada, and Mexico. They administer the same questionnaire to another 10,000 people from the same countries who do not have a diagnosis of anxiety disorder. Their findings are tabulated below.

Since 1999, The Harris Poll has conducted an annual survey to measure the reputations of the most visible companies in the United States, as perceived by U.S. adults. The Harris Poll uses a sample of about 23,000 U.S. adults for the survey. The survey respondents rate companies according to 20 attributes that are classified into six categories: (1) social responsibility, (2)vision and leadership, (3)financial Performance ,(4)products and services, (5) emotional appeal, and (6) workplace environment. This information is used to determine the reputation of a company. Reputations of 10 Companies in the U.S. Company Name Year Company formed Reputation Industry Number of Employees Amazon.com 1994 Excellent Retail 230,800 Apple Inc 1977 Excellent Computer and peripherals 116,000 Netflix Inc 1999 Very good Internet Television 4,700 The Kraft Heinz Co 2015 Very good Food products  41,000 Facebook Inc 2004 good Internet…

Tim is interested in studying whether Cognitive Behavioural Therapy (CBT) is an effective treatment for Obsessive Compulsive Disorder (OCD). Six people who were diagnosed with OCD participated in Tim's study, where he recorded the number of times they washed their hands per day for one month. They were then given a three week intensive CBT program before their hand-washing was monitored for another month. The average number of times per day each participant washed their hands over the two months of observation are as follows: Participant Month 1 Month 2 1 11 6 2 8 5 3 14 17 4 10 10 5 22 11 6 15 10   Compute the appropriate statistic to determine whether the program was effective and use this information to fill in the blanks:   Q1. revealed that the number of times per day participants washed their hands following the CBT program was Q2. compared to the number of times per day participants washed their hands before the…

The president of a mid-sized state university has proposed lowering tuition rates in order to increase the school’s overall graduation rates (meaning she expects the two measures will be negatively associated with each other). She collects data on other similar universities, rating universities as “high” on tuition (above-average tuition costs) or “low” (below average tuition), as well as on their proportion of students who graduate in six years (categorizing with those graduating more than half of their students as “high” and those graduating fewer than half as “low”). A bivariate table with these data is below. Calculate the gamma and then write a sentence or two interpreting what it suggests about the relationship. Is there support for the president’s hypothesis?   Graduation Rate by Tuition Rate   Tuition Rate Graduation Rate Low High Totals Low   52    40 92 High   80   125 205 Totals 132 165 297

Philosophical and health issues are prompting an increasing number of Taiwanese to switch to a vegetarian lifestyle. A study published in the Journal of Nutrition compared the daily intake of nutrients by vegetarians and omnivores living in Taiwan. Among the nutrients considered was protein. Too little protein stunts growth and interferes with all bodily functions; too much protein puts a strain on the kidneys, can cause diarrhea and dehydration, and can leach calcium from bones and teeth. Independent random samples of 51 female vegetarians and 53 female omnivores yielded the following summary statistics, in grams, on daily protein intake. Vegetarians: ?" = 39.04, ? = 18.82, ? = 51  Omnivores: ?" = 49.92, ? = 18.97, ? = 53  Do the data provide sufficient evidence to conclude that the mean daily protein intakes of female vegetarians and female omnivores differ? Perform the required hypothesis test at the 1% significance level. Assume equality of variances. Determine a 99%…

1. The percentage of 12- to 17-year-olds who reported talking at least once in the past year with their parents about the dangers of drug, tobacco, or alcohol is 60% nationally. A state youth council believes this proportion is higher in their state, where there has been an intense media campaign about this issue. A survey of randomly chosen students from across the state shows 1032 of 1642 students reporting they are having these conversations with their parents. Is there evidence that the percent of students using drugs, tobacco or alcohol in this state is above the national rate?

Philosophical and health issues are prompting an increasing number of Taiwanese to switch to a vegetarian lifestyle. A study published in the Journal of Nutrition compared the daily intake of nutrients by vegetarians and omnivores living in Taiwan. Among the nutrients considered was protein. Too little protein stunts growth and interferes with all bodily functions; too much protein puts a strain on the kidneys, can cause diarrhea and dehydration, and can leach calcium from bones and teeth. Independent random samples of 51 female vegetarians and 53 female omnivores yielded the following summary statistics, in grams, on daily protein intake. Vegetarians: X₁ = 39.04, s₁ = 18.82, n₁ = 51 Omnivores: X₂ = 49.92, S₂: 18.97, n₂ = 53 a. Do the data provide sufficient evidence to conclude that the mean daily protein intakes of female vegetarians and female omnivores differ? Perform the required hypothesis test at the 1% significance level. Assume equality of variances. b. Determine a 99%…

A study prospectively examined whether sleep-disordered breathing was associated with an increased risk of death from any cause in a cohort of 600 adults participating in the Sleep Heart Health Study. Study participants were classified into four groups depending on the extent of their sleep-disordered breathing (none, mild, moderate, or severe). The counts of deaths over the course of the study are reported for each group in the following two-way table. Mild Severe 100 Death No Death Total None 40 100 140 40 100 140 Moderate 20 100 120 Total 200 400 600 100 200 We want to know whether the study findings give evidence of a significant difference of the number of deaths between the different groups. Set up the alternative hypothesis (H, : The distribution of the categorical variable is not as given by the null hypothesis (lack of fit) At least ones of the means is different from the others O The two categorical variables are dependent The distribution of the categorical variable is not…

A study prospectively examined whether sleep-disordered breathing was associated with an increased risk of death from any cause in a cohort of 600 adults participating in the Sleep Heart Health Study. Study participants were classified into four groups depending on the extent of their sleep-disordered breathing (none, mild, moderate, or severe). The counts of deaths over the course of the study are reported for each group in the following two-way table. Death No Death Total None 40 100 140 Mild 40 100 140 Moderate 20 100 120 Severe 100 100 200 Total 200 400 600 We want to know whether the study findings give evidence of a significant difference of the number of deaths between the different groups. The observed test statistic is 3.610 42.857 5.476 8.075