Introduction To Statistics And Data Analysis
6th Edition
ISBN: 9781337793612
Author: PECK, Roxy.
Publisher: Cengage Learning,
expand_more
expand_more
format_list_bulleted
Textbook Question
Chapter 7.7, Problem 108E
The figure on the next page appeared in the paper “EDTA-Extractable Copper, Zinc, and Manganese in Soils of the Canterbury Plains” (New Zealand Journal of Agricultural Research [1984]: 207–217). A large number of topsoil samples were analyzed for manganese (Mn), zinc (Zn), and copper (Cu), and the resulting data were summarized using histograms.
The investigators transformed each data set using logarithms in an effort to obtain more nearly symmetric distributions of values. Do you think the transformations were successful? Explain.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
The following table gives the U.S. population, ages 20–64, (in millions) for selected years from 1950 and projected to 2050.
Year
Millions
Year
Millions
1950
92.8
2010
189.1
1960
99.8
2020
198.2
1970
113.0
2030
202.8
1980
134.0
2040
213.3
1990
152.7
2050
224.3
2000
169.8
(a)
Find the logistic function that models these data. Use x as the number of years after 1950 and report your model with 3 significant digit coefficients.
y =
251(1+2.56e(−0.0273x))
(b)
Use the unrounded model to predict the U.S. population (in millions) ages 20–64 in 2005. (Round your answer to one decimal place.)
million
(c)
What year does the unrounded model predict this group's population will reach 200 million?
The following data represents the growth of bacteria population over time
A manufacturer claims that the tensile strength of a certain composite (in MPa) has the lognormal distribution with μ = 5 and σ = 0.5. Let X be the strength of a randomly sampled specimen of this composite. a) If the claim is true, what is P(X < 20)? b) Based on the answer to part (a), if the claim is true, would a strength of 20 MPa be unusually small? c) If you observed a tensile strength of 20 MPa, would this be convincing evidence that the claim is false? Explain. d) If the claim is true, what is P(X < 130)? e) Based on the answer to part (d), if the claim is true, would a strength of 130 MPa be unusually small? f) If you observed a tensile strength of 130 MPa, would this be convincing evidence that the claim is false? Explain.
Chapter 7 Solutions
Introduction To Statistics And Data Analysis
Ch. 7.1 - State whether each of the following random...Ch. 7.1 - Classify each of the following random variables as...Ch. 7.1 - Starting at a particular time, each car entering...Ch. 7.1 - A point is randomly selected from the interior of...Ch. 7.1 - A point is randomly selected on the surface of a...Ch. 7.1 - Prob. 6ECh. 7.1 - A box contains four slips of paper marked 1, 2, 3,...Ch. 7.2 - Define the random variable x to be the number of...Ch. 7.2 - Using the probability distribution given in the...Ch. 7.2 - Let y denote the number of broken eggs in a...
Ch. 7.2 - Use the probability distribution given in the...Ch. 7.2 - Suppose that fund-raisers at a university call...Ch. 7.2 - Airlines sometimes overbook flights. Suppose that...Ch. 7.2 - Suppose that a computer manufacturer receives...Ch. 7.2 - Simulate the chance experiment described in the...Ch. 7.2 - Of all airline flight requests received by a...Ch. 7.2 - Suppose that 20% of all homeowners in an...Ch. 7.2 - A box contains five slips of paper, marked 1, 1,...Ch. 7.2 - Components coming off an assembly line are either...Ch. 7.2 - When applying for a building permit, a contractor...Ch. 7.2 - A library subscribes to two different weekly news...Ch. 7.3 - Let x denote the lifetime (in thousands of hours)...Ch. 7.3 - Using the density curve for fan lifetime given in...Ch. 7.3 - A particular professor never dismisses class...Ch. 7.3 - Refer to the probability distribution given in the...Ch. 7.3 - The article Probabilistic Risk Assessment of...Ch. 7.3 - Use the density curve of x = distance of actual...Ch. 7.3 - Let x denote the amount of gravel sold (in tons)...Ch. 7.3 - Use the density curve for x = amount of gravel...Ch. 7.3 - Let x be the amount of time (in minutes) that a...Ch. 7.3 - Ref erring to the previous exercise, let x and y...Ch. 7.3 - The density curve for the random variable w (the...Ch. 7.4 - Consider selecting a household in rural Thailand...Ch. 7.4 - Suppose the probability distribution of x, the...Ch. 7.4 - Consider the following probability distribution...Ch. 7.4 - Referring to the previous exercise, use the result...Ch. 7.4 - Exercise 7.8 gave the following probability...Ch. 7.4 - Prob. 38ECh. 7.4 - Prob. 39ECh. 7.4 - Refer to the information given in Exercise 7.39....Ch. 7.4 - Refer to the information given in Exercise 7.39....Ch. 7.4 - Suppose that for a particular computer...Ch. 7.4 - A local television station sells 15-second,...Ch. 7.4 - An author has written a book and submitted it to a...Ch. 7.4 - A grocery store has an express line for customers...Ch. 7.4 - An appliance dealer sells three different models...Ch. 7.4 - To assemble a piece of furniture, a wood peg must...Ch. 7.4 - A multiple-choice exam consists of 50 questions....Ch. 7.4 - Consider a game in which a red die and a blue die...Ch. 7.4 - Consider the random variables xR and xB defined in...Ch. 7.5 - CBS News reported that 4% of adult Americans have...Ch. 7.5 - Flight View surveyed 2600 North American airline...Ch. 7.5 - Refer to the previous exercise, and suppose that...Ch. 7.5 - Twenty-five percent of the customers of a grocery...Ch. 7.5 - Example 7.18 described a study in which a person...Ch. 7.5 - Information Security Buzz provides news for the...Ch. 7.5 - A breeder of show dogs is interested in the number...Ch. 7.5 - Womens Health Magazine surveyed 1187 readers to...Ch. 7.5 - Prob. 60ECh. 7.5 - Suppose that the probability is 0.1 that any given...Ch. 7.5 - Suppose that 30% of all automobiles undergoing an...Ch. 7.5 - Suppose that you will take a multiple-choice exam...Ch. 7.5 - Suppose that 20% of the 10,000 signatures on a...Ch. 7.5 - A city requires that smoke detectors be installed...Ch. 7.5 - Suppose that 90% of all registered California...Ch. 7.5 - Suppose a playlist on a music player consists of...Ch. 7.5 - Sophie is a dog that loves to play catch....Ch. 7.5 - Suppose that 5% of cereal boxes contain a prize...Ch. 7.6 - Determine the following standard normal (z) curve...Ch. 7.6 - Determine the following standard normal (z) curve...Ch. 7.6 - Determine each of the following areas under the...Ch. 7.6 - Determine each of the following areas under the...Ch. 7.6 - Let z denote a random variable that has a standard...Ch. 7.6 - Let z denote a random variable that has a standard...Ch. 7.6 - Let z denote a random variable having a normal...Ch. 7.6 - Let z denote a random variable having a normal...Ch. 7.6 - Let z denote a variable that has a standard normal...Ch. 7.6 - Determine the value z that a. Separates the...Ch. 7.6 - Determine the value of z such that a. z and z...Ch. 7.6 - Because P(z 0.44) = 0.67, 67% of all z values are...Ch. 7.6 - Consider the population of all 1-gallon cans of...Ch. 7.6 - Consider babies born in the normal range of 3743...Ch. 7.6 - Use the information on birth weights for babies...Ch. 7.6 - Emissions of nitrogen oxides, which are major...Ch. 7.6 - The paper referenced in Example 7.30 (Estimating...Ch. 7.6 - The size of the left upper chamber of the heart is...Ch. 7.6 - The paper referenced in the previous exercise also...Ch. 7.6 - The article New York Citys Graffiti-Removal...Ch. 7.6 - A machine that cuts corks for wine bottles...Ch. 7.6 - Refer to the previous exercise. Suppose that there...Ch. 7.6 - Purchases made at small corner stores were studied...Ch. 7.6 - The time that it takes a randomly selected job...Ch. 7.6 - Suppose that the distribution of typing speed in...Ch. 7.6 - Consider the typing speed distribution described...Ch. 7.6 - Consider the typing speed distribution described...Ch. 7.7 - The authors of the paper Development of...Ch. 7.7 - The paper Risk Behavior, Decision Making, and...Ch. 7.7 - Prob. 99ECh. 7.7 - Prob. 100ECh. 7.7 - Macular degeneration is the most common cause of...Ch. 7.7 - The following normal probability plot was...Ch. 7.7 - Consider the following 10 observations on the...Ch. 7.7 - Prob. 104ECh. 7.7 - Prob. 105ECh. 7.7 - Prob. 106ECh. 7.7 - Prob. 107ECh. 7.7 - The figure on the next page appeared in the paper...Ch. 7.8 - Let x denote the IQ of an individual selected at...Ch. 7.8 - Suppose that the distribution of x = the number of...Ch. 7.8 - The number of vehicles leaving a turnpike at a...Ch. 7.8 - Suppose that x has a binomial distribution with n...Ch. 7.8 - Prob. 113ECh. 7.8 - Prob. 114ECh. 7.8 - Prob. 115ECh. 7.8 - Suppose that 70% of the bicycles sold by a certain...Ch. 7.8 - Suppose that 25% of the fire alarms in a large...Ch. 7.8 - Suppose that 65% of all registered voters in a...Ch. 7.8 - Flashlight bulbs manufactured by a certain company...Ch. 7.8 - A company that manufactures mufflers for cars...Ch. 7 - Let x denote the duration of a randomly selected...Ch. 7 - A soft-drink machine dispenses only regular Coke...Ch. 7 - A business has six customer service telephone...Ch. 7 - Prob. 124CRCh. 7 - Refer 10 the probability distribution given in...Ch. 7 - A new batterys voltage may be acceptable (A) or...Ch. 7 - A pizza company advertises that it puts 0.5 pounds...Ch. 7 - Suppose that fuel efficiency for a particular...Ch. 7 - A coin is flipped 25 times. Let x be the number of...Ch. 7 - The probability distribution of x, the number of...Ch. 7 - The amount of time spent by a statistical...Ch. 7 - The lifetime of a certain brand of battery is...Ch. 7 - A machine producing vitamin E capsules operates so...Ch. 7 - The Wall Street Journal (February 15, 1972)...Ch. 7 - The longest run of Ss in the sequence SSFSSSSFFS...Ch. 7 - Four peoplea, b, c, and dare waiting to give...Ch. 7 - Kyle and Lygia are going to play a series of...Ch. 7 - Suppose that your statistics professor tells you...Ch. 7 - Suppose that the pH of soil samples taken from a...Ch. 7 - The lightbulbs used to provide exterior lighting...Ch. 7 - Suppose there are approximately 40,000 travel...Ch. 7 - Prob. 2CRECh. 7 - Prob. 3CRECh. 7 - Prob. 5CRECh. 7 - Prob. 6CRECh. 7 - Two shipping services offer overnight delivery of...Ch. 7 - Prob. 8CRECh. 7 - Prob. 9CRECh. 7 - The Cedar Rapids Gazette (November 20, 1999)...Ch. 7 - Prob. 11CRECh. 7 - The article Men, Women at Odds on Gun Control...Ch. 7 - Suppose that a new Internet company Mumble.com...Ch. 7 - Refer to the previous exercise. Suppose that...Ch. 7 - A chemical supply company currently has in stock...Ch. 7 - Prob. 16CRECh. 7 - An experiment was conducted to investigate whether...Ch. 7 - A machine that produces ball bearings has...Ch. 7 - Consider the variable x = time required for a...Ch. 7 - The accompanying data on x = student-teacher ratio...Ch. 7 - Prob. 21CRE
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.Similar questions
- Table 6 shows the population, in thousands, of harbor seals in the Wadden Sea over the years 1997 to 2012. a. Let x represent time in years starting with x=0 for the year 1997. Let y represent the number of seals in thousands. Use logistic regression to fit a model to these data. b. Use the model to predict the seal population for the year 2020. c. To the nearest whole number, what is the limiting value of this model?arrow_forwardThe following table gives the percentage, PP, of households with a television set that also have a VCR. Year 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 % having VCR 0.2 0.4 0.7 1.4 2.5 5.2 9.4 16.5 24.5 35.6 44.4 53.7 55.0 63.0 (a) During what year does the point of "diminishing returns" (i.e., the inflection point) appear to take place? (b) If the best fitting logistic function for this data is P=63/1+350e^−0.68t (where tt is years since 1978) what is the limiting value (as tt gets very large)? (c) What is the exact difference (in absolute value), if any, between the value predicted by the given function and the value stated in the table for the year 1983?arrow_forwardConsider the following panel model to examine the effect of retirement on consumption expenditure, consit, of individual i over years t=1,…,3: (B1) log(consit) = β0 + β1retiredit + β2ageit + β3marriedit + β4healthit + δ1Yr2t + δ2Yr3t + ai + uit Where: retiredit is a dummy variable equal to 1 if individual i is retired on year t and 0 otherwise ageit is the individual's age in years marriedit is an indicator variable for whether the individual is married (1) or not (0) in year t healthit is an indicator variable equal to 1 if the individual is in 'good health' and 0 otherwise Yr2 is a dummy variable equal to 1 in year t=2 and 0 otherwise Yr3 is a dummy variable equal to 1 in year t=3 and 0 otherwise Using the information above, answer the following 3 questions. [i] Give two (2) examples of the kind of variables captured by the term ai in Model (B1). [ii] What is the crucial assumption we must make so that the random effects (RE) estimator is consistent? Under this assumption, why is…arrow_forward
- The article “Assessment of Dermopharmacokinetic Approach in the Bioequivalence Determination of Topical Tretinoin Gel Products” (L. Pershing, J. Nelson, et al., J Am Acad Dermatol 2003:740–751) reports that the amount of a certain antifungal ointment that is absorbed into the skin can be modeled with a lognormal distribution. Assume that the amount (in ng/cm²) of active ingredient in the skin two hours after application is lognormally distributed with μ = 2.2 and σ = 2.1. a) Find the mean amount absorbed. b) Find the median amount absorbed. c) Find the probability that the amount absorbed is more than 100 ng/cm². d) Find the probability that the amount absorbed is less than 50 ng/cm². e) Find the 80th percentile of the amount absorbed. f) Find the standard deviation of the amount absorbed.arrow_forwardSuppose a logistic regression analysis of some data for restaurants gave the following result, in terms of L, which here represents the logit, that is, the log odds, lnOdds. L(x1, x2) = .3 − .2x1 + .1x2, where Y = 1 denotes closing within one year of startup,Y = 0 denotes staying in business more than one year , X1 = 1 if franchised, 0 if not,X2 = 1 if a fast-food restaurant, 0 if not,Px = Pr{Y = 1|x1,x2}, Qx = Pr{Y = 0|x1,x2},L(x1, x2) = ln(Px1,x2 /Qx1,x2 ) = logit(Px1,x2 ) 1. What is the value of L(0, 1) ? (A) .1 (B) .2 (C) .3 (D) .4 (E) .5 2. The number P(Y = 1|X1 = 0,X2 = 1) is the probability that (A) a franchised fast-food restaurant is bankrupt within one year. (B) a franchised non-fast food restaurant is not bankrupt within one year. (C) a non-franchised fast-food restaurant is bankrupt within one year. (D) a non-franchised non-fast food restaurant is bankrupt within one year. (E) a fast-food restaurant is franchised. 3. (continuation) What is the value of…arrow_forwardSam was 28 inches tall on her first birthday, 50 inches tall on her 8th, and 62 inches tall on her 14th. (a) Let t represent Sam's age in years, and let h represent her height in inches. Determine the values of M, A, and k for a logistic model, h(t) = M / ( 1+ Ae-kt) , that fits the given height data. (b) What is Sam's theoretical long-term expected height? That is, what is limt➔∞h(t)? (c) At what age does the model predict that Sam will reach 95% of her expected maximum height?arrow_forward
- Find the data that yields the given log-likelihood ?(?;data)arrow_forwardThe following table shows world population N, in billions, in the given year. According to the logistic model N = 10.90 / 1+2.23e^-0.030t, when will world population reach 90% of carrying capacity? Year N 1965 3.38 1970 3.72 1975 4.15 1980 4.48 1985 4.87 1990 5.38 1995 5.72 1999 6.05 a) 2064b) 2069c) 2066d) 2094arrow_forwardA study was conducted among patients with retinitis pigmentosa, an ocular condition where pigment appears over the retina, resulting in substantial loss of vision in many cases. The study was based on 94 patients who were seen annually at a baseline visit and three annual follow-up visits. In this study, 90 patients provided visual-field measurements at each of the four examinations and are the subject of the following data analyses. Visual field was transformed to the natural logarithm (ln) scale to better approximate normality and yielded the data given in the table below: Assuming that a change in visual field over 3 years is normally distributed when using the ln scale, what is the proportion of patients who showed a decline in visual field over 3 years? What percentage of patients would be expected to show a decline of at least 20% in visual field over 3 years? (Note: In the ln scale this is equivalent to a decline of at least ln (1/0.8) = 0.223). What percentage of patients…arrow_forward
- Consider a simple model to explain a country’s alcohol related automobiles incidents (totaai) in terms of police police officers (topps): Estimating (a) using quarterly data from 1991-2024 gives: log(totaait) = 12.58 − 0.66 log(topps); (2.22) (0.33) n = 95; R2 = :439; 3. Suppose that both total alcohol incidents (totaai) and total police officers (totts) have a positive trend. Given this information, discuss whether the OLS estimates of ˛1 from equation (a) is unbiased (i.e., E(˛ˆ 1) = ˛1)?arrow_forwardThe following table contains statistics from a logistic regression analysis for a study on intravenous drug use among high school students in United States. Drug use is characterized as a dichotomous variable, where 1 indicates that an individual has injected drugs within the past year and 0 that he or she has not. Factors that might be related to drug use are instruction about the HIV in school (1 represents "had HIV education" and 0 represents "did not have HIV education"), age of the student (in years), and gender (1 represents male and 0 represents female). Statistics in the table are estimated coefficients of the logistic regression model and p-values for testing the significance of the coefficients. Choose proper answers using statistics in the following table. (THERE MAY BE MORE THAN ONE CORRECT ANSWER) Variable Coefficient p-value Intercept (Constant) -0.164 0.078 HIV instruction 0.019 0.928 Age 0.064 0.036 Gender 1.032 0.014…arrow_forwardtable 3 gives the actual sales, log of sales, and changes in the log of sales of Cisco Systems for the period 1Q:2001 to 4Q:2001. 10. a. having an out-of-sample rMSe of 20 percent. The ar(1) model for the civilian unemployment rate, Δuert = −0.0405 − 0.4674Δuert −1, was developed with five years of data. what would be the drawback to using the ar(1) model to predict changes in the civilian unemployment rate 12 months or more ahead, as compared with one month ahead? table 3 Date Quarter: year 1Q:2001 2Q:2001 3Q:2001 4Q:2001 1Q:2002 2Q:2002 actual Sales ($ Millions) 6,519 6,748 4,728 4,298 log of Sales 8.7825 8.8170 8.4613 8.3659 Changes in log of Sales Δln (Salest) 0.1308 0.0345 −0.3557 −0.0954 Forecast the first- and second-quarter sales of Cisco Systems for 2002 using the regression Δln (Salest) = 0.0661 + 0.4698Δln (Salest −1).arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Algebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:CengageGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:9781133382119
Author:Swokowski
Publisher:Cengage
Glencoe Algebra 1, Student Edition, 9780079039897...
Algebra
ISBN:9780079039897
Author:Carter
Publisher:McGraw Hill
Implicit Differentiation with Transcendental Functions; Author: Mathispower4u;https://www.youtube.com/watch?v=16WoO59R88w;License: Standard YouTube License, CC-BY
How to determine the difference between an algebraic and transcendental expression; Author: Study Force;https://www.youtube.com/watch?v=xRht10w7ZOE;License: Standard YouTube License, CC-BY