Preliminary data analyses indicate that you can reasonably apply the z-interval procedure (Procedure 8.1 on page 339) in Exercises 8.69–8.74.
8.71 Toxic Mushrooms? Cadmium, a heavy metal, is toxic to animals. Mushrooms, however, are able to absorb and accumulate cadmium at high concentrations. The Czech and Slovak governments have set a safety limit for cadmium in dry vegetables at 0.5 part per million (ppm). M. Melgar et al. measured the cadmium levels in a random sample of the edible mushroom Boletus pinicola and published the results in the paper “Influence of Some Factors in Toxicity and Accumulation of Cd from Edible Wild Macro fungi in NW Spain (Journal of Environmental Science and Health, Vol. B33(4), pp. 439–455). Here are the data obtained by the researchers.
Find and interpret a 99% confidence interval for the
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Introductory Statistics (10th Edition)
- Please solve part d and e only. The body mass index (BMI) of a person is defined to be the person’s body mass divided by the square of the person’s height. The article “Influences of Parameter Uncertainties within the ICRP 66 Respiratory Tract Model: Particle Deposition” (W. Bolch, E. Farfan, et al., Health Physics, 2001:378–394) states that body mass index (in kg/m2) in men aged 25–34 is lognormally distributed with parameters μ = 3.215 and σ = 0.157. a.Find the mean and standard deviation BMI for men aged 25–34. b.Find the standard deviation of BMI for men aged 25–34. c.Find the median BMI for men aged 25–34. d.What proportion of men aged 25–34 have a BMI less than 20? e.Find the 80th percentile of BMI for men aged 25–34.arrow_forwardBased on long-term investigation, researchers have suggested that the acidity (pH) of rainfall in the Shenandoah Mountains can be described by the Normal model N(4.9, 0.6). Show your work while answering the following questionsarrow_forwardradon is a colorless, odorless gas that is naturally released by rocks and soils and may concentrate in tightly closed houses. because radon is slightly radioactive, there is some concern that it may be a health hazard. radon detectors are sold to homeowners worried about this risk, but the detectors may be inaccurate. university researchers placed 12 detectors in a chamber where they were exposed to 105 picocuries per liter (pci/l) of radon over 3 years. here are the readings given by the detectors:91.9 97.8 111.4 112.3 105.4 85.0 103.8 89.6 96.6 109.3 104.8 91.7 Assume (unrealistically) that you know that the standard deviation of readings for all detectors of this type is σ = 9. a. Give the 95% confidence interval for the mean reading μ for this type of detector. b. Is there significant evidence at the 5% level that the mean reading differs from the true value 105? State hypotheses and base a test on your confidence interval from (a). c. Calculate the power of this test against the…arrow_forward
- Special dyes have been developed that only bind to DNA. The intensity of the color is directly related to the quantity of DNA present in the cell. A haploid cell would have a “low” amount of color, a cell in G1 would have a “medium” amount of color, and a cell in M phase would have a “high” amount of color. Is this sort of assessment quantitative, qualitative or semi-quantitative? Justify your reasoning.arrow_forwardThe American Mineralogist (Oct. 2009) published a study of the evolution of uranium minerals in the Earth's crust. Researchers estimate that the trace amount of uranium x in reservoirs follows a uniform distribution ranging between 1 and 3 parts per million. Complete parts a through c. a. Find E(x) and interpret its value. Select the correct answer below and fill in the answer box to complete your choice. (Simplify your answer.) O A E(X)= . This value gives the minimum parts per million of uranium for the collection of all reservoirs on the Earth. O B. E(x)= This value gives the maximum parts per million of uranium for the collection of all reservoirs on the Earth. CC E(x)= 2. This value gives the mean parts per million of uranium for the collection of all reservoirs on the Earth. OD. E(X) = This value gives the mean parts per million of uranium in each reservoir on the Earth. b. Compute P(2arrow_forward3.2 Evaluate the value of e²dz using Simpson's rule.arrow_forwardApproximately 281.000,000 people over age five live in the United States. Of these people, 55,000,000 speak a language other than English at home. Of those who speak another language at home, 62.3 percent speak Spanish. E= speaks English at home • E'= speaks another language at home •S= speaks Spanish at home What is P(E')? I.arrow_forwardOver the past 10 years, contestants at the county fair hotdog eating contest averaged 125 hotdogs within the 1 minute time frame. Due to Covid19 restrictions, there were only 15 contestants who ate an average of 122 hotdogs. s=6.5 We're interested in finding out if there is significant change in hotdog eating. Use the hypothesis that H0: µ=125, Ha: #125. What is the SE? 10.9 1.7 6.5 8.3arrow_forwardResearchers collected data to examine the relationship between pollutants and preterm births in Southern California. During the study air pollution levels were measured by air quality monitoring stations. Specifically, levels of carbon monoxide were recorded in parts per million, nitrogen dioxide and ozone in parts per hundred million, and coarse particulate matter PM10 in µg/m3. Length of gestation data were collected on 143,196 births between the years 1989 and 1993, and air pollution exposure during gestation was calculated for each birth. The analysis suggested that increased ambient PM10 and, to a lesser degree, CO concentrations may be associated with the occurrence of preterm births. a. The paragraph above describes an O A. Observational Study B. Experiment b. The cases in this research are OA. Air pollution exposure during gestation B. Each birth between 1989 and 1993 C. Each type of pollution measured by air quality monitoring stations D. Each year between 1989 and 1993 c.…arrow_forwardThe following table gives the millions of metric tons of carbon dioxide emissions in a certain country for selected years from 2010 and projected to 2012 2010 2012 2014 2016 336.5 363.5 398.1 Year CO, Emissions 2018 424.8 451.1 Year 2022 2024 2026 2028 2030 Co, Emissions 559.2 591.9 628.7 665.1 707.1 2020 2032 743.7 Using x as the number of years past 2010 and y as the millions of metric tons of carbon dioxide emissions, write the equation of the linear function that models these data. (Round all numerical values to two decimal places.) Hint: Let x 0 in 2010. y(x) =arrow_forwardExercise 2.250 introduces a study showing thatfluoride exposure might have long-term negativeconsequences for the offspring of pregnant women.Part of the study examines the effect of adding flu-oride to tap water on mean fluoride concentrationin women. Summary statistics for fluoride concen-tration (measured in mg/L) for the two groups are given in Table 6.17. Find and interpret a 99% con-fidence interval for the mean increase in fluorideconcentration for those with fluoridated tap water. Answer the above questions in picture. Tap water Sample size mean St.Dev --------------- --------------- -------- ------ Fluoridated : 141 0.69 0.42 non-fluoridated 228 0.40 0.27arrow_forwardThe following are the cystatin C levels (mg/L) for the patients described in Exercise 15 (A-17).Cystatin C is a cationic basic protein that was investigated for its relationship to GFR levels. Inaddition, creatinine levels are also given. (Note: Some subjects were measured more than once.)Cystatin C (mg/L) Creatinine (mmol/L)1.78 4.69 0.35 0.142.16 3.78 0.30 0.111.82 2.24 0.20 0.091.86 4.93 0.17 0.121.75 2.71 0.15 0.071.83 1.76 0.13 0.122.49 2.62 0.14 0.111.69 2.61 0.12 0.071.85 3.65 0.24 0.101.76 2.36 0.16 0.131.25 3.25 0.17 0.091.50 2.01 0.11 0.122.06 2.51 0.12 0.062.34Source: Data provided courtesy of D. M. Z. Krieser, M.D.(a) For each variable, compute the mean, median, variance, standard deviation, and coefficient ofvariation.(b) For each variable, construct a stem-and-leaf display and a box-and-whisker plot.(c) Which set of measurements is more variable, cystatin C or creatinine? On what do you base youranswer?arrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_ios
- Linear Algebra: A Modern IntroductionAlgebraISBN:9781285463247Author:David PoolePublisher:Cengage Learning