Consider a proposed case-control study of autism spectrum disorder (ASD) and maternal boba tea consumption in Irvine. Assume that 20% of Irvine mothers are regular consumers (at least 3 servings per week) of boba tea, and that the prevalence of ASD is 1/59 (making it a somewhat rare disease). Also assume that 50% of Irvine mothers who regularly consume boba tea prefer black milk tea, that the prevalence of regular boba tea consumption among mothers of autistic children is 25%, that each participant will be paid $30 to join the study, and that there are at least 1,000 mothers of autistic children and at least 100,000 mothers of non-autistic children in Irvine who are willing to participate in the study if compensated. If these assumptions are correct, what is the odds ratio describing the association between regular boba tea consumption and ASD? HINT: Recall that the disease odds ratio is equal to the exposure odds ratio.

Productivity is the key driver of wages and one of the most importantdeterminants of living standards. The British Chambers of Commercecommissioned research into understanding whether labour productivity in theautomotive manufacturing sector in England and Ireland were the same ordifferent. The researchers collected data on a random sample of 8 firms inEngland and 4 in Ireland and recorded productivity in units of value added (£)per hour. It is assumed that firm-level productivity has a normal distribution.The following data were collected:Ireland 47 56 43 68England 39 50 39 45 50 43 35 43(i) Set up appropriate null and alternative hypotheses and conduct a test ofthe hypotheses of equal mean productivity in Ireland and England at 5 percent significance level under the assumption of unknown but equalpopulation variances. Provide as much detail as possible on yourprocedures. Clearly show all your steps in testing and state your decision.Discuss the economic implications of your findings.…

Researchers studying the link between prenatal vitamin use and autism surveyed the mothers of a random sample of children aged 24 - 60 months with autism and surveyed another separate random sample for children with typical development. Table summarizing the number of mothers in each group who did and did not use prenatal vitamins during the three months before pregnancy (data from Schmidt, 2011) Autism Typical Development Total No vitamin 111 70 181 Vitamin 143 159 302 Total 254 229 483 Complete the hypothesis test for independence between the two variables, use of prenatal vitamins during the three months before pregnancy and autism in Rguroo. What is the value of the test statistic for this test? (Use the Large Sample Z method and please round to two decimal places)

More than 10% of people carry the parasite Toxoplasma gondii. The life-long presence of Toxoplasma cysts in neural and muscular tissues leads to prolongation of reaction times in infected subjects. The following table gives data from Prague on 15- to 29-year-old drivers who had been and had not been involved in accidents. The table also gives the number of drivers who were infected with Toxoplasma gondii and who were uninfected. Infected Uninfected Drivers with accidents 21 38 Drivers without accidents 38 211 Source: Flegr. J Havlicek, J., Kodym, P. Malý, M. & Smahel, Z. (2002). Increased risk of traffic accidents in subjects with latent toxoplasmosis: a retrospective case- control study. BMC infectious diseasex, 2, 11. https://doi.org/10.1186/1471-2334-2-11 Complete the sentences to form the correct statements identifying the explanatory and response variables. Select from here: infection status. The explanatory variable is place of living. accident state. The response variable is age…

Beryllium is an extremely lightweight metal that is used in many industries, such as aerospace and electronics. Long-term exposure to beryllium can cause people to become sensitized. Once an individual is sensitized, continued exposure can result in chronic beryllium disease, which involves scarring of the lungs. In a study of the effects of exposure to beryllium, workers were categorized by their duration of exposure (in years) and by their disease status (diseased, sensitized, or normal). The results were as follows:     Duration of Exposure   <1 1 to <5 ≥5 Diseased 14 13 18 Sensitized 11 20 15 Normal 78 140 209 Test the hypothesis of independence. Use the a=0.10 level of significance and the P-value method with the TI-84 Plus calculator. What do you conclude? State the null and alternate hypotheses.

Sleep apnea is a disorder characterized by pauses in breathing during sleep. Children who suffer from untreated sleep apnea often have behavior problems, including hyperactivity, inattention, and aggression. A common treatment for pediatric sleep apnea is the surgical removal of enlarged tonsils and adenoids that are obstructing the airways. Suppose researchers at a sleep clinic are interested in the effect of surgical treatment for pediatric sleep apnea on aggressive behavior. They study 11 children without sleep apnea, 11 children with untreated sleep apnea, and 11 children who have been surgically treated for sleep apnea. Aggression is measured using the Conners Rating Scales. The sample means and sums of squares of the scores for each of the three groups are presented in the following table. Group Sample Mean Sum of Squares No Sleep Apnea 0.59 0.3240 Untreated Sleep Apnea 0.45 0.4410 Treated Sleep Apnea 0.31 0.2250   The researchers perform an analysis of…

Hutchinson-Gilford progeria syndrome is a rare genetic condition that produces rapid aging in children. In individuals with this syndrome, cardiovascular disease is a common cause of death in the teenage years. A clinical study examined the effect of treatment with the drug lonafarnib on a number of physiological outcomes. The researchers measured the pulse wave velocity (PWV) of 18 children diagnosed with progeria and recruited worldwide. The study reports that the mean PWV of 18 children diagnosed with progeria is 12.44 m/s, and the standard deviation is 3.638 m/s. Assuming that PWV is normally distributed, is there significant evidence that the mean PWV of children with progeria is abnormally high (i.e. greater than 6.6 m/s)? Let �  (pronounced as "mu") be the true mean PWV of children with progeria.  What are the two competing hypotheses?       ["", "", "", ""]  What is the test statistic?       ["", "", "", ""]  What is the p value?       ["", "", "", ""]  What is the rejection…

Suppose we are interested in studying the relationship between the shelf life of cheeses in a dairy factory and the thickness of the packaging material used for those cheeses. We would like to determine if there is a causal relationship between the thickness of the packaging material and the shelf life of the cheese; that is, does a change in the thickness of the packaging material cause a change in the shelf life of the cheese? Select the study that would be best source of evidence for establishing the existence of a causal relationship. Select one: O a. A study which uses a stratified random sample, stratifying by type of cheese, to select units of cheese in the factory and determine the thickness of the packaging material and test the shelf life of each unit. O b. A study which uses a cluster sample, clustering by room the cheese is stored in, to select units of cheese in the factory and determine the thickness of the packaging material and test the shelf life of each unit. O c. A…

Trans-Generational Effects of Diet Can experiences of parents affect future children? New studies16 suggest that they can: Early life experiences of parents appear to cause permanent changes in sperm and eggs. In one study, some male rats were fed a high-fat diet with 43% of calories from fat (a typical American diet), while others were fed a normal healthy rat diet. Not surprisingly, the rats fed the high-fat diet were far more likely than the normal-diet rats to develop metabolic syndrome (characterized by such things as excess weight, excess fat, insulin resistance, and glucose intolerance.) What surprised the scientists was that the daughters of these rats were also far more likely to develop metabolic syndrome than the daughters of rats fed healthy diets. None of the daughters and none of the mothers ate a high-fat diet and the fathers did not have any contact with the daughters. The high-fat diet of the fathers appeared to cause negative effects for their daughters. What are the…

A study was made of 413 children who were hospitalized as a result of motor vehicle crashes. Among 290 children who were not using seat belts, 60 were injured severely. Among 123 children using seat belts, 16 were injured severely (based on data from "Morbidity Among Pediatric Motor Vehicle Crash Victims: The Effectiveness of Seat Belts," by Osberg and Di Scala, American Journal of Public Health, Vol. 82, No. 3). For this problem we want to know, is there sufficient sample evidence to conclude, at the 0.05 significance level, that the proportion of severe injuries is higher for children not wearing seat belts? Let pi be the proportion of severe injuries among all children not wearing seatbelts and who were involved in crashes. Let p2 be the proportion of severe injuries among all children wearing seatbelts and who were involved in crashes. Which is the proper expression of Ho? Pi = P2 O Pi P2 Which is the proper expression of H1? O pi P2 Calculate p1 to 4 decimal places: Calculate p,…