9. Auto Exhaust and Lead ExposureResearchers interested in lead exposure due to car exhaust sampled the bloodof 19 police officers subjected to constant inhalation of automobile exhaust fumeswhile working traffic enforcement in a primarily urban environment. The bloodsamples of these officers had an average lead concentration of 11.2µg/dl and aSD of 4.5µg/dl; a previous study of individuals from a nearby suburb, with nohistory of exposure, found an average blood level concentration of 7.2μg/dl.(a) Test the hypothesis that the downtown police officers have a higher leadexposure than the officers in the previous study. Be sure to interpret your resultsin context. a = = 0.05(b) Explicitly state and check all conditions necessary for inference on thisdata.(c) Based on your preceding result, without performing a calculation, woulda 90% confidence interval for this difference contain 0? Explain why or why not.

The question is about hypo. testing and confidence interval Given : Randomly selected no. of police…

Answered: 9. Auto Exhaust and Lead Exposure…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

Inorganic phosphorous is a naturally occurring element in all plants and animals, with concentrations increasing progressively up the food chain (fruit < vegetables < cereals < nuts < corpse). Geochemical surveys take soil samples to determine phosphorous content (in ppm, parts per million). A high phosphorous content may or may not indicate an ancient burial site, food storage site, or even a garbage dump. Independent random samples from two regions gave the following phosphorous measurements (in ppm). Assume the distribution of phosphorous is mound-shaped and symmetric for these two regions. Region I: x,; n, = 15 875 1,080 2,330 1,850 1,860 853 1,551 1,230 2,340 1,080 910 1,130 1,450 1,260 1,010 Region II: x,; n, = 14 540 808 790 1,230 1,770 960 1,650 860 890 640 1,180 1,160 1,050 | 1,020 In USE SALT (a) Use a calculator with mean and standard deviation keys to verify that x,, S,, x2, and s,. (Round your answers to four decimal places.) X1 ppm S. = ppm X2 ppm 52 ppm (b) Let u, be the…
A deficiency of the trace element selenium in the diet can negatively impact growth, immunity, muscle and neuromuscular function, and fertility. The introduction of selenium supplements to dairy cows is justified when pastures have low selenium levels. Authors of a research paper supplied the following data on milk selenium concentration (mg/L) for a sample of cows given a selenium supplement (the treatment group) and a control sample given no supplement, both initially and after a 9-day period. Initial Measurement Treatment Control 11.4 9.1 9.6 8.7 10.1 9.7 8.5 10.8 10.2 10.9 10.6 10.6 11.9 10.1 9.9 12.3 10.7 8.8 10.2 10.4 10.3 10.9 11.4 10.4 9.3 11.6 10.6 10.9 10.9 8.3 After 9 Days Treatment Control 138.3 9.2 104 8.9 96.4 8.9 89 10.1 88 9.6 103.8 8.6 147.3 10.4 97.1 12.4 172.6 9.2 146.3 9.5 99 8.4 122.3 8.8 103 12.5 117.8 9.1 121.5 93 (a) Use the given data for the treatment group to determine if…
A longitudinal study was conducted to investigate if a 3 week "Green" program can change people's attitude's towards recycling. Participants were randomly allocated into two groups: (1) those who received the Green program and (2) those who did not receive the Green program. Each participant completed a survey (measured on a metric scale) which measured their attitudes towards recycling at the end of each week of the study. It was hypothesised that those in the Green program would have more positive attitudes towards recycling compared to those in the non Green group. It was also hypothesised that this difference would be largest at the end of week 3 of the study. Which of the following would be an appropriate statistical test to conduct, which addresses these hypotheses? Group of answer choices: Within subjects ANOVA Mixed ANOVA Single factor ANOVA Factorial ANOVA Multiple Regression
Water availability is of prime importance in the life cycle of most reptiles. To determine the rate of evaporative water loss of a certain species of lizard at a particular desert site, 34 such lizards were randomly collected, weighed and placed under the appropriate experimental conditions. After 24 hours, each lizard was removed, weighed, and its total water loss was calculated by subtracting its body weight after treatment from its initial body weight. Previous studies have shown that the relative frequency distribution of water loss for this species of lizard has a mean of 3.1 grams and a s.d. of 0.8 gram. a) What is the approximate sampling distribution of x , the mean water loss of the 34 lizards
Tardigrades, or water bears, are a type of micro-animal famous for their resilience. In examining the effects of radiation on organisms, an expert claimed that the amount of gamma radiation needed to sterilize a colony of tardigrades no longer has a mean of 1350 Gy (grays). (For comparison, humans cannot withstand more than 10 Gy .) A study was conducted on a sample of 18 randomly selected tardigrade colonies, finding that the amount of gamma radiation needed to sterilize a colony had a sample mean of 1375 Gy , with a sample standard deviation of 75 Gy . Assume that the population of amounts of gamma radiation needed to sterilize a colony of tardigrades is approximately normally distributed. Complete the parts below to perform a hypothesis test to see if there is enough evidence, at the 0.05 level of significance, to support the claim that μ , the mean amount of gamma radiation needed to sterilize a colony of tardigrades, is not equal to 1350 Gy .
Consider the following studies. Study I: A researcher randomly divided 200 high school students into two groups. The first group was told to not exercise. The second group was told to exercise at least 5 hours each week. At the end of two months, the heart rates of each participant in each group were measured at rest. It was found that the group that exercised 5 hours a week had a significantly lower average heart rate. Study II: A researcher gathered 200 high school students randomly, asked them how long they exercised each week, and then measured their heart rates at rest. It was found that students who exercised at least 5 hours a week had a significantly lower average heart rate. Part A: Which study was experimental? Why? Study IStudy II Part B: List the explanatory and response variables in the studies. Explanatory: heart rate; Response: exercise timeExplanatory: student; Response: amount of exerciseExplanatory: exercise time; Response: heart rate Part C: State whether the…
In a population-based cohort study, an entire community was interviewed regarding smoking habits and then followed for one year. Upon ascertainment of all lung cancer deaths, the investigator obtained the following data: Number of Individuals Lung Cancer Deaths Smokers 24,500 15 Nonsmokers 10,500 2 Calculate the risk difference per 100,000 per year. Round to the tenth decima
Fluoride Exposure in Drinking Water Exercise 2.250 introduces a study showing that fluoride exposure might have long-term negative consequences for the offspring of pregnant women. Part of the study examines the effect of adding fluoride to tap water on mean fluoride concentration in women. Summary statistics for fluoride concentration (measured in mg/L) for the two groups are given in the table below. Tap water Fluoridated Non-fluoridated Conclusion: Sample size 141 228 Mean 0.69 0.40 St.Dev. 0.42 0.27 Find and interpret a 99% confidence interval for the mean increase in fluoride concentration for those with fluoridated tap water. Let Group 1 represent those with fluoridated tap water and Group 2 represent those without fluoridated tap water. Confidence interval: i to i (round to three decimal places)
Denny studied factors affecting cardiovascular reactivity to a postural change in a sample of healthy men and women. Change in systolic blood pressure (SBP) from supine to standing position was used as the measure of cardiac reactivity in a sample of 842 adults. Supine measurement of blood pressure was taken after participants had lain on an examination table for 15 minutes. Blood pressure was determined every 30 seconds using a Dinamap device for 2 minutes, and the measurements were averaged. Participants then stood up immediately, and additional measurements were made for another 2 minutes. Below is a table describing the characteristics of Denny’s sample: Which measures of dispersion, if any, are presented in this table (Ranges, SDs)? If age is normally distributed, approximately what percent of the sample would be younger than 50? If BMI is normally distributed, approximately what percent of the sample would have a BMI higher than 33.1?
The authors of the paper "Statistical Methods for Assessing Agreement Between Two Methods of Clinical Measurement"† compared two different instruments for measuring a person's ability to breathe out air. (This measurement is helpful in diagnosing various lung disorders.) The two instruments considered were a Wright peak flow meter and a mini-Wright peak flow meter. Seventeen people participated in the study, and for each person air flow was measured once using the Wright meter and once using the mini-Wright meter. Subject Mini-WrightMeter WrightMeter Subject Mini-WrightMeter WrightMeter 1 512 494 10 445 433 2 430 395 11 432 417 3 520 516 12 626 656 4 428 434 13 260 267 5 500 476 14 477 478 6 600 557 15 259 178 7 364 413 16 350 423 8 380 442 17 451 427 9 658 650 (a) Suppose that the Wright meter is considered to provide a better measure of air flow, but the mini-Wright meter is easier to transport and to use. If the two types of meters produce…
Water availability is of prime importance in the life cycle of most reptiles. To determine the rate of evaporative water loss of a certain species of lizard at a particular desert site, 34 such lizards were randomly collected, weighed and placed under the appropriate experimental conditions. After 24 hours, each lizard was removed, weighed, and its total water loss was calculated by subtracting its body weight after treatment from its initial body weight. Previous studies have shown that the relative frequency distribution of water loss for this species of lizard has a mean of 3.1 grams and a s.d. of 0.8 gram b) What is the probability that x is less than 2.7 grams?

Recommended textbooks for you

MATLAB: An Introduction with Applications

Statistics

ISBN:

9781119256830

Author:

Amos Gilat

Publisher:

John Wiley & Sons Inc

Probability and Statistics for Engineering and th…

Statistics

ISBN:

9781305251809

Author:

Jay L. Devore

Publisher:

Cengage Learning

Statistics for The Behavioral Sciences (MindTap C…

Statistics

ISBN:

9781305504912

Author:

Frederick J Gravetter, Larry B. Wallnau

Publisher:

Cengage Learning

MATLAB: An Introduction with Applications

Statistics

ISBN:

9781119256830

Author:

Amos Gilat

Publisher:

John Wiley & Sons Inc

Probability and Statistics for Engineering and th…

Statistics

ISBN:

9781305251809

Author:

Jay L. Devore

Publisher:

Cengage Learning

Statistics for The Behavioral Sciences (MindTap C…

Statistics

ISBN:

9781305504912

Author:

Frederick J Gravetter, Larry B. Wallnau

Publisher:

Cengage Learning

Elementary Statistics: Picturing the World (7th E…

Statistics

ISBN:

9780134683416

Author:

Ron Larson, Betsy Farber

Publisher:

PEARSON

The Basic Practice of Statistics

Statistics

ISBN:

9781319042578

Author:

David S. Moore, William I. Notz, Michael A. Fligner

Publisher:

W. H. Freeman

Introduction to the Practice of Statistics

Statistics

ISBN:

9781319013387

Author:

David S. Moore, George P. McCabe, Bruce A. Craig

Publisher:

W. H. Freeman

SEE MORE TEXTBOOKS