Concept explainers
Vitamin B6 is one of the vitamins in a multiple vitamin pill manufactured by a pharmaceutical company. The pills are produced with a
A consumer group suspects that
(a) Define a critical region to test
(b) If the 20 pills yielded a mean of
(c) What is the approximate p-value of this test?
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Probability and Statistical Inference (9th Edition)
- What does the y -intercept on the graph of a logistic equation correspond to for a population modeled by that equation?arrow_forwardRetinitis pigmentosa (RP) is a hereditary ocular diseasein which patches of pigment appear on the retina, potentially resulting in substantial vision loss and in somecases complete blindness. An important issue is how fastthe subjects decline. Visual field is an important measureof area of vision, which is measured in degree2. A visualfield area for a normal person is around 11,000 degree2.The longitudinal data in Table 11.29 were provided by anindividual patient.Table 11.29 Longitudinal visual field data forone RP patientTime Visual field area lnVisit (yr) (degree2) (visual field area)1 0 3059 8.032 1 3053 8.023 2 1418 7.264 3 1692 7.435 4 1978 7.596 5 1567 7.367 6 1919 7.568 7 1998 7.609 11 1648 7.4110 13 1721 7.4511 15 1264 7.14mean 6.09 1938 7.532sd 4.97 597 0.280Suppose the rate of change of ln (visual field) is a linearfunction of follow-up time.11.103 Write down a linear regression model that summarizes this relationship.11.104 Fit the regression line using the method of…arrow_forwardDo wearable devices that monitor diet and physical activity help people lose weight? Researchers had 237 subjects who were already involved in a program of diet and exercise use wearable technology for 24 months. They measured their weight (in kilograms) before using the technology and 24 months after using the technology. The 237 differences in weight (weight after 24 months minus weight before using the wearable technology) had x = -3.5 and s = 7.8. Let u be the mean weight difference. 41 John M. Jakicic et al., "Effect of wearable technology combined with a lifestyle intervention on long-term weight loss, the IDEA randomized clinical trial," JAMA, 316, 2016, pp. 1161-1171. O Macmillan Learning " What is the test statistic? Give your answer to three decimal places. What is the P-value? The P-value is between 0.01 and 0.05. The P-value is less than 0.0005. O The P-value is between 0.0005 and 0.01. The P-value is greater than 0.05.arrow_forward
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- OphthalmologyRetinitis pigmentosa (RP) is a hereditary ocular diseasein which patches of pigment appear on the retina, potentially resulting in substantial vision loss and in somecases complete blindness. An important issue is how fastthe subjects decline. Visual field is an important measureof area of vision, which is measured in degree2. A visualfield area for a normal person is around 11,000 degree2.The longitudinal data in Table 11.29 were provided by anindividual patient.Table 11.29 Longitudinal visual field data forone RP patientTime Visual field area lnVisit (yr) (degree2) (visual field area)1 0 3059 8.032 1 3053 8.023 2 1418 7.264 3 1692 7.435 4 1978 7.596 5 1567 7.367 6 1919 7.568 7 1998 7.609 11 1648 7.4110 13 1721 7.4511 15 1264 7.14mean 6.09 1938 7.532sd 4.97 597 0.280Suppose the rate of change of ln (visual field) is a linearfunction of follow-up time.11.103 Write down a linear regression model that summarizes this relationship.11.104 Fit the regression line using…arrow_forwardA researcher is interested in testing the relationship between smoking and BMI (kg/m2) in adults aged 30-45. In order to test this association, the researcher divides smoking into currently more than a pack a day, currently less than a pack a day, and never smokers. The following table represents the BMIs for each participant enrolled by their respective smoking category. Current Smoker (≥1pack/day) Current Smoker (<1 pack/day Never Smoked 26.7 29.4 22.1 29.4 28.6 30.4 24.3 27.4 21.3 28.4 23.2 26.4 21.6 20.1 19.7 27.4 20.6 19.8 26.8 19.7 21.6 36.4 19.6 22.3 31.5 21.6 24.3 27.4 21.5 *Continue as though all assumptions for ANOVA are met. A) Calculate the MSW and MSB for the data represented above. B) Carry out a formal test for a one-way analysis of variance among the groups and interpret your results.arrow_forwardStudies have shown that people who suffer sudden cardiac arrest have a better chance of survival if a defibrillator shock is administered very soon after cardiac arrest. How is survival rate related to the time between when cardiac arrest occurs and when the defibrillator shock is delivered? The accompanying data give y = survival rate (percent) and x = mean call-to-shock time (minutes) for a cardiac rehabilitation center (in which cardiac arrests occurred while victims were hospitalized and so the call-to-shock time tended to be short) and for four communities of different sizes: Mean call-to-shock time, x Survival rate, y The data were used to compute the equation of the least-squares line, which was ŷ = 100.90 9.21x. A newspaper article reported that "every minute spent waiting for paramedics to arrive with a defibrillator lowers the chance of survival by 10 percent." Is this statement consistent with the given least-squares line? Explain. O Since the slope of the least-squares line…arrow_forward
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