Researchers at a medical school want to compare the rates of birth defects in babies born to mothers with low-fat diets with those born to mothers with high-fat diets. For one year, they collected data on all babies and their mothers in area hospitals, using information obtained from the mothers to determine whether they fall in the low fat or high fat diet category. A) Observational B) Experimental

Researchers at a medical school want to compare the rates of birth defects in babies born to mothers with low-fat diets with those born to mothers with high-fat diets. For one year, they collected data on all babies and their mothers in area hospitals, using information obtained from the mothers to determine whether they fall in the low fat or high fat diet category. A) Observational B) Experimental

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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Of all sports, football accounts for the highest incidence of concussion in the United States due to the large number of athletes participating and the nature of the sport. While there is general agreement that concussion incidence can be reduced by making rule changes and teaching proper tackling technique, there remains debate as to whether helmet design may also reduce the incidence of concussion. Rowson et al. (2014) report on a retrospective analysis of head impact data collected between 2005 and 2010 from eight collegiate football teams. Concussion rates for players wearing two types of helmets, Riddell VSR4 and Riddell Revolution, were compared. A total of 1,281,444 head impacts were recorded, from which 64 concussions were diagnosed. The relative risk of sustaining a concussion in a Revolution helmet compared with a VSR4 helmet was 46.1%. This study illustrates that differences in the ability to reduce concussion risk exist between helmet models in football. Although helmet…
A company surveyed adult Americans about their consumer debt. The article reported that 48% of millennials (those born between 1980 and 1996) and 62% of Gen Xers (those born between 1965 and 1971) did not pay off their credit cards each month, and therefore carried a balance from month to month. Suppose that these percentages were based on representative samples of 450 millennials and 300 Gen Xers. Is there convincing evidence that the proportion of Gen Xers who do not pay off their credit cards each month is greater than this proportion for millennials? Test the appropriate hypotheses using a significance level of 0.05. (Let p1 be the proportion of Gen Xers who do not pay off their credit cards each month, and p2 be the proportion of Millennials who do not pay off their credit cards each month.) State the appropriate null and alternative hypotheses. H0: p1 − p2 = 0 Ha: p1 − p2 > 0 H0: p1 − p2 = 0 Ha: p1 − p2 < 0 H0: p1 − p2 > 0 Ha: p1 − p2 < 0 H0: p1 − p2 <…
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.
The following is data about the hemoglobin concentrations of volunteers collected at sea level and at an altitude of 11000 feet. sea level concentrations = [14.70 , 15.22, 15.28, 16.58, 15.10 , 15.66, 15.91, 14.41, 14.73, 15.09, 15.62, 14.92]11000 feet concentrations = [14.81, 15.68, 15.57, 16.59, 15.21, 15.69, 16.16, 14.68, 15.09, 15.30 , 16.15, 14.76] There are two alternative scenarios about the way the data were obtained. In scenario 1, there are 12 volunteers who lived for a month at sea level, at which time blood was drawn and the data in "sea level concentrations" dataset were obtained. Subsequently, all 12 volunteers were moved to 11000 ft and after a month the data in the "11000 feet concentrations" dataset obtained. There is a one to one correspondence between the numbers in the two datasets, that is the first numbers correspond to volunteer1, the second numbers to volunteer2 etc. In scenario 2, the "sea level concentrations" dataset is a random sample obtained from 12…
Of all sports, football accounts for the highest incidence of concussion in the United States due to the large number of athletes participating and the nature of the sport. While there is general agreement that concussion incidence can be reduced by making rule changes and teaching proper tackling technique, there remains debate as to whether helmet design may also reduce the incidence of concussion. Rowson et al. (2014) report on a retrospective analysis of head impact data collected between 2005 and 2010 from eight collegiate football teams. Concussion rates for players wearing two types of helmets, Riddell VSR4 and Riddell Revolution, were compared. A total of 1,281,444 head impacts were recorded, from which 64 concussions were diagnosed. The relative risk of sustaining a concussion in a Revolution helmet compared with a VSR4 helmet was 46.1%. This study illustrates that differences in the ability to reduce concussion risk exist between helmet models in football. Although helmet…
A bank branch located in a commercial district of a city has the business objective of developing an improved process for serving customers during the noon-to-1:00 P.M. lunch period. The waiting time, in minutes, is defined as the time the customer enters the line to when he or she reaches the teller window. Data are collected from a sample of 15 customers during this hour. Another bank branch, located in a residential area, is also concerned with the noon-to-1 P.M. lunch hour. The waiting times, in minutes, are also collected from a sample of 15 customers during this hour. Complete parts (a) through (c) below. The following is the list of time data gathered from the bank branch in the commercial district. 4.55 5.89 3.44 5.03 4.08 2.25 3.65 3.58 4.69 6.03 0.66 5.72 6.17 6.65 3.38 The following is the list of time data gathered from the bank branch in the residential district. 9.44 5.07 8.98 5.13 8.87…
A study used ethnographic interview techniques, not usually part of ethnography, and quantitative questionnaires to answer questions about how young children (ages 9 to 15) are socialized into sports. How can researchers report coherently on the findings using these apparently incompatible data collection techniques?
The article "Vehicle-Arrival Characteristics at Urban Uncontrolled Intersections" (V. Rengaraju and V. Rao, Journal of Transportation Engineering, 1995: 317-323) presents data on traffic characteristics at 10 intersections in Madras, India. One characteristic measured was the speeds of the vehicles traveling through the intersections. The accompanying table gives the 15th, 50th, and 85th percentiles of speed (in km/h) for two intersections. Percentile Intersection 15th 50th 85th 27.5 37.5 40.0 в 24.5 26.5 36.0 If a histogram for speeds of vehicles through intersection A were drawn, would it most likely be skewed to the left, skewed to the right, or approximately symmetric? Explain. b. If a histogram for speeds of vehicles through intersection B were drawn, would it most likely be skewed to the left, skewed to the right, or approximately symmetric? Explain. a.
A bank branch located in a commercial district of a city has the business objective of developing an improved process for serving customers during the noon-to-1:00 P.M. lunch period. The waiting time, in minutes, is defined as the time the customer enters the line to when he or she reaches the teller window. Data are collected from a sample of 15 customers during this hour. Another bank branch, located in a residential area, is also concerned with the noon-to-1 P.M. lunch hour. The waiting times, in minutes, are also collected from a sample of 15 customers during this hour. Complete parts (a) through (c) below. The following is the list of time data gathered from the bank branch in the commercial district. 4.74 5.93 3.63 5.38 4.19 2.86 3.84 3.21 4.09 6.48 0.84 5.41 6.04 6.42 3.31 The following is the list of time data gathered from the bank branch in the residential district. 9.67 5.82 8.63 5.97 8.03…
Patients suffering from rheumatic diseases or osteoporosis often suffer critical losses in bone mineral density (BMD). Alendronate is one medication prescribed to build or prevent further loss of BMD. Holcomb and Rothenberg (A-3) looked at 96 women taking alendronate to determine if a difference existed in the mean percent change in BMD among five different primary diagnosis classifications. Group 1 patients were diagnosed with rheumatoid arthritis (RA). Group 2 patients were a mixed collection of patients with diseases including lupus, Wegener’s granulomatosis and polyarteritis, and other vasculitic diseases (LUPUS). Group 3 patients had polymyalgia rheumatica or temporal arthritis (PMRTA). Group 4 patients had osteoarthritis (OA) and group 5 patients had osteoporosis (O) with no other rheumatic diseases identified in the medical record. Changes in BMD are shown in the following table. (TABLE IS IN THE IMAGES) a. Formulate research question b. State the null hypothesis in narrative…
A) Classify the following data as either qualitative data or quantitative data. In addition, classify the quantitative data as discrete or continuous. The number of times that a movement authority is sent to a train from a relay station is recorded for several trains Over a three-week period. The movement authority, which is an electronic transmission, is sent repeatedly until a return signal is received from the train. 1. 2. A physician records the follow-up condition of patients with optic neuritis as improved, unchanged, or worse. The individuals in a sociological study are classified into one of five income classes as follows: low, low to middle Middle, middle to upper, or upper. 3.
A bank branch located in a commercial district of a city has the business objective of developing an improved process for serving customers during the noon-to-1:00 P.M. lunch period. The waiting time, in minutes, is defined as the time the customer enters the line to when he or she reaches the teller window. Data are collected from a sample of 15 customers during this hour. Another bank branch, located in a residential area, is also concerned with the noon-to-1 P.M. lunch hour. The waiting times, in minutes, are also collected from a sample of 15 customers during this hour. Complete parts (a) through (c) below. The following is the list of time data gathered from the bank branch in the commercial district. 4.55 5.89 3.44 5.03 4.08 2.25 3.65 3.58 4.69 6.03 0.66 5.72 6.17 6.65 3.38 The following is the list of time data gathered from the bank branch in the residential district. 9.44 5.07 8.98 5.13 8.87 3.86…