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)
- “Normal” BMI is up to 25 kg/m2. A laboratory study is being conducted to determine energy expenditure for those who are overweight and/or obese. The researchers have enrolled only subjects with BMI above 25.0 and have quantified obesity as “units above normal”. For example, a subject with BMI of 32.3 is recorded as 7.3 (i.e. 32.3 – 25.0 = 7.3). Using this scheme, the mean obesity was found to be 8.7 kg/m2and the standard deviation was 6.4 kg/m2. If we convert the obesity measure used in this study back into conventional BMI (i.e., add 25.0 units to each measurement), what will the standard deviation be? Group of answer choices The standard deviation will be larger on the BMI scale because 25.0 units will be added back. The standard deviation will be the same 6.4 kg/m2 There is not enough information to determine this The standard deviation will be smaller on the BMI scale because, as a percentage of the whole scale, the difference between each subject and the mean will be…arrow_forwardIn the period of 2010 – 2020 in the United States 1/3 of patients 55 years old or older had a seasonal flu vaccine. The risk of death for a flu-vaccinated person 55 years or older in the following 10 months is 0.6 deaths per 1,000 flu-vaccinated persons 55 years old or older. The risk of death for a non-vaccinated 55 year old or older person in the same 10 month period is 5 deaths per 1,000. Given these numbers, what is the probability that a person 55 years or older in the United States will survive 10 months into that year's flu season?arrow_forwardpaper 2 4. INDICES AND SURDS page 7 2004 N Q1 Given that Va+b/3 4+ 3 13 where a and b are integers, find, without using a calculator, the value %3D of a and of b.arrow_forward
- The minister of environment in a certain country decided to investigate whether expansion of a aluminum plant in that country would affect fluoride pollution in it's environment. The productions occurred the years 2005 and 2006. One of the things measured was the amount of fluoride in lamb jaws. The data available are measurements of fluoride in the jaws of 8 lambs that were slaughtered in the year 2004 and 8 lambs that were slaughtered in the year 2007. The data is shown below, along with a R output that can simplify your calculations. Fluoride amount 2004 (ug/g) | Fluoride amount 2007 (ug/g) 131.37 655.09 252.74 541.37 81.29 564.58 225.55 617.97 222.44 472.54 68.29 606.62 227.55 500.80 111.86 394.67 > fs2004 fs2007 mean (fs2004) [1] 165.1363 > mean (fs2007) [1] 544.205 > var (fs2004) [1] 5555.906 > var (fs2007) [1] 7348.022 > d mean (d) [1] 379.0688 > var (d) [1] 14657.70arrow_forward3.2 Evaluate the value of e²dz using Simpson's rule.arrow_forwardA researcher wonders whether younger mothers have babies that are significantly heavier or lighter than the population average of μ 7.25 pounds. The researcher collects data from N = 35 babies who were born to mothers between the ages of 16 and 18. The average weight for these babies was M = 7.15 pounds (SD = .6 pounds).arrow_forward
- Please helparrow_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_forwardPlease review Section 11.1. Are you an impulse shopper? A survey of 500 grocery shoppers indicated that 16% of males and 42% of females make an impulse purchase every time they shop. Assume that the survey consisted of 250 males and 250 females. Let group 1 be the males and let group 2 be the females. a = 0.05 H :T, = T, H :T, # T, Calculate the test statistic: (Round to three decimal places as needed.) Determine the critical value: (Round to three decimal places as needed.) State the Conclusion:arrow_forward
- summarraize the concentration of the drug in the bloodstream for the first 20 hours afetr it is taken. use the findings from a-e to validate your statementsarrow_forwardA production process is currently operating at + 4.5 a level. a. Calculate the nonconforming ratio for the current process. b. Calculate the nonconforming ratio if the process mean shifts by 1.5 o. ignore the cell belowarrow_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_forward
- Linear Algebra: A Modern IntroductionAlgebraISBN:9781285463247Author:David PoolePublisher:Cengage Learning