Do certain behaviors result in a severe drain on energy resources because a great deal of energy is expended in comparison to energy intake? The article “The Energetic Cost of Courtship and Aggression in a Plethodontid Salamander” (Ecology [1983]: 979–983) reported on one of the few studies concerned with behavior and energy expenditure. The accompanying table gives oxygen consumption (mL/g/hr) for male-female salamander pairs.
a. The pooled t test is a test procedure for testing H0: μ1 – μ2, = hypothesized value when it is reasonable to assume that the two population distributions are normal with equal standard deviations (σ1 = σ2,). The test statistic for the pooled t test is obtained by replacing both s1 and s2 in the two-sample t test statistic with sp where
When the population distributions are normal with equal standard deviations and H0 is true, the resulting pooled t statistic has a t distribution with df = n1 + n2 – 2. For the reported data, the two sample standard deviations are similar. Use the pooled t test with α = 0.05 to determine whether the mean oxygen consumption for courting pairs is higher than the mean oxygen consumption for noncourting pairs.
b. Would the conclusion in Part (a) have been different if the two-sample t test had been used rather than the pooled t test?
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Chapter 11 Solutions
Introduction to Statistics and Data Analysis
- Urban Travel Times Population of cities and driving times are related, as shown in the accompanying table, which shows the 1960 population N, in thousands, for several cities, together with the average time T, in minutes, sent by residents driving to work. City Population N Driving time T Los Angeles 6489 16.8 Pittsburgh 1804 12.6 Washington 1808 14.3 Hutchinson 38 6.1 Nashville 347 10.8 Tallahassee 48 7.3 An analysis of these data, along with data from 17 other cities in the United States and Canada, led to a power model of average driving time as a function of population. a Construct a power model of driving time in minutes as a function of population measured in thousands b Is average driving time in Pittsburgh more or less than would be expected from its population? c If you wish to move to a smaller city to reduce your average driving time to work by 25, how much smaller should the city be?arrow_forwardIn a study, the effects of the mane of a male lion as a signal of quality to mates and rivals was explored. Four life-sized dummies of male lions provided a tool for testing female response to the unfamiliar lions whose manes varied by length (long or short) and color (blonde or dark). The female lions were observed to see whether they approached each of the four life-sized dummies. Complete parts (a) through (e) below. a. Identify the experimental units. Choose the correct answer below. The female lions The male dummies The mane colors The mane lengths Part 2 b. Identify the response variable. Choose the correct answer below. A. Whether or not (yes or no) the mane length affected how the female lions reacted to a male dummy. B. Whether or not (yes or no) the female lions approached the same dummies. C. Whether or not (yes or no) the female lions approached a male dummy. D. Whether or not…arrow_forwardThe Journal of Engineering in Industry (Aug. 1993) reported on an automated system designed to replace the cutting tool of a drilling machine at optimum times. To test the system, data were collected over a broad range of materials, drill sizes, drill speeds, and feed rates – called machining conditions. Although a total of 168 different machining conditions were possible, only eight were employed in this study. These are described below: Experiment Workpiece Drill Size (in.) 25 25 Drill Speed (грт) 1250 1800 Feed Rate Material (ipr) .011 .005 1 Cast Iron Cast Iron Steel Steel 25 25 3750 2500 .003 .003 .008 4 Steel 25 .125 .125 2500 Steel Steel 4000 4000 3000 .0065 .009 .010 Steel .125 a. Suppose one (and only one) of the 168 possible machining conditions will detect a flaw in the system. What is the probability that the experiment conducted in the study will detect the system flaw? b. Suppose the system flaw occurs when drilling steel material with a 25-inch drill size at a speed of…arrow_forward
- 5.1 Application: Yo. e Here is data for the amount of fat (in grams) for McDonald's chicken sandwiches: Sandwich McChicken Ⓒ Premium Grilled Chicken Classic Sandwich Premium Crispy Chicken Classic Sandwich Premium Grilled Chicken Club Sandwich Premium Crispy Chicken Club Sandwich Premium Grilled Chicken Ranch BLT Sandwich Premium Crispy Chicken Ranch BLT Sandwich Southern Style Crispy Chicken Sandwich Ranch Snack Wrap (Crispy) Ranch Snack Wrap (Grilled) Honey Mustard Snack Wrap (Crispy). Honey Mustard Snack Wrap (Grilled) Chipotle BBQ Snack Wrap (Crispy) Chipotle BBQ Snack Wrap (Grilled) Find the median and IQR. M = type your answer... IQR= type your answer... C 54 do 5 % Fat 16 g 10 g 20 g 17 g 28 g 12 g 23 g 17 g 17 g 10 g 16 g 99 15 g 99 A 6 g g DELL & 7 O 8 O ( 9 % ) 0arrow_forwardVegetarians and Omnivores. Philosophical and health issues are prompting an increasing number of Taiwanese to switch to a vegetarian lifestyle. In the paper “LDL of Taiwanese Vegetarians Are Less Oxidizable than Those of Omnivores” (Journal of Nutrition, Vol. 130, pp. 1591–1596), S. Lu et al. compared the daily intake of nutrients by vegetarians and omnivores living in Taiwan. Among the nutrients considered was protein. Too little protein stunts growth and interferes with all bodily functions; too much protein puts a strain on the kidneys, can cause diarrhea and dehydration, and can leach calcium from bones and teeth. The daily protein intakes, in grams, for 51 female vegetarians and 53 female omnivores are provided on the WeissStats site. Use the technology of your choice to do the following for each of the two sets of sample data. a. Obtain a histogram of the data and use it to assess the (approximate) normality of the variable under consideration. b. Obtain a normal probability plot…arrow_forwardAn article in the Journal of Sound and Vibration (Vol. 151, 1991, pp. 383-394) described a study investigating the relationship between noise exposure and hypertension. The following data are representative of those reported in the article. ... ух ух 1 60 5 85 0 63 4 89 1 65 6 90 2 70 8 90 5 70 4 90 1 70 5 90 4 80 7 94 6 90 9 100 2 80 7 100 3 80 6 100 Fit a linear regression model relating blood pressure rise in millimeters of mercury (y) to sound pressure level in decibels (x) using least squares. Does a simple linear regression model (slope) seem reasonable in this situation? Input Yes or No. Blank 1 What are the least squares estimate of the slope? Input answer up to 3 decimal places, i.e., 0.000. Blank 2arrow_forward
- The toco toucan, the largest member of the toucan family, possesses the largest beak relative to body size of all birds. This exaggerated feature has received various interpretations, such as being a refined adaptation for feeding. However, the large surface area may also be an important mechanism for radiating heat (and hence cooling the bird) as outdoor temperature increases. The table contains data for beak heat loss, as a percentage of total body heat loss from all sources, at various temperatures in degrees Celsius. The data show that beak heat loss is higher at higher temperatures and that the relationship is roughly linear. [Note: The numerical values in this problem have been modified for testing purposes.] Temperature (°C) 15 16 17 18 19 20 21 22 23 24 25 26 27 Percent heat loss from beak 33 33 33 31 37 44 56 52 45 54 46 55 57arrow_forwardThe toco toucan, the largest member of the toucan family, possesses the largest beak relative to body size of all birds. This exaggerated feature has received various interpretations, such as being a refined adaptation for feeding. However, the large surface area may also be an important mechanism for radiating heat (and hence cooling the bird) as outdoor temperature increases. The table contains data for beak heat loss, as a percentage of total body heat loss from all sources, at various temperatures in degrees Celsius. The data show that beak heat loss is higher at higher temperatures and that the relationship is roughly linear. [Note: The numerical values in this problem have been modified for testing purposes.] Temperature (Co) Percent heat loss from beak 15 32 16 34 17 35 18 33 19 37 20 46 21 55 22 51 23 43 24 52 25 45 26 53 27 58 28 60 29 62 30 62 Adapted from a graph in Glenn J. Tattersall et al., "Heat exchange from the toucan bill…arrow_forwardThe toco toucan, the largest member of the toucan family, possesses the largest beak relative to body size of all birds. This exaggerated feature has received various interpretations, such as being a refined adaptation for feeding. However, the large surface area may also be an important mechanism for radiating heat (and hence cooling the bird) as outdoor temperature increases. The table contains data for beak heat loss, as a percentage of total body heat loss from all sources, at various temperatures in degrees Celsius. The data show that beak heat loss is higher at higher temperatures and that the relationship is roughly linear. [Note: The numerical values in this problem have been modified for testing purposes.] Temperature (oC)(oC) Percent heat loss from beak 1515 3434 1616 3535 1717 3333 1818 3333 1919 3535 2020 4848 2121 5454 2222 5252 2323 4545 2424 5050 2525 4444 2626 5454 2727 5959 2828 6262 2929 6464 3030 6161 Adapted from a graph in…arrow_forward
- The Great White Shark. In an article titled “Great White, Deep Trouble” (National Geographic, Vol. 197(4), pp. 2–29), Peter Benchley—the author of JAWS—discussed various aspects of the Great White Shark (Carcharodon carcharias). Data on the number of pups borne in a lifetime by each of 80 Great White Shark females are provided on the WeissStats site. a. obtain and interpret the quartiles. b. determine and interpret the interquartile range. c. find and interpret the five-number summary. d. identify potential outliers, if any. e. obtain and interpret a boxplot.arrow_forwardResearchers measured the distribution of beak sizes in a cohort of medium ground finch hatchlings in the Galapagos Islands in 1976 just before, and in a cohort of hatchlings two years after a severe drought. They measured 100 finches in each cohort. After the drought, the proportion of large, harder seeds was substantially greater than before the drought. Their data documenting this selective event are shown in graphical and tabular form below. Beak size (mm) Frequency before selection Frequency after selection 10.010.0 0.000.00 0.000.00 10.210.2 0.000.00 0.000.00 10.410.4 0.020.02 0.000.00 10.610.6 0.040.04 0.000.00 10.810.8 0.080.08 0.000.00 11.011.0 0.160.16 0.000.00 11.211.2 0.200.20 0.000.00 11.411.4 0.200.20 0.000.00 11.611.6 0.160.16 0.020.02 11.811.8 0.080.08 0.040.04 12.012.0 0.040.04 0.080.08 12.212.2 0.020.02 0.160.16 12.412.4 0.000.00 0.200.20 12.612.6 0.000.00 0.200.20 12.812.8 0.000.00 0.160.16 13.013.0 0.000.00 0.080.08 13.213.2…arrow_forwardResearchers were interested in better understanding how autistic children see and understand the world. Participants included children diagnosed with autism and typically- developing children, who were all approximately the same age. All children were presented with several different stimuli on a large computer screen for up to one minute. The stimuli were both social (i.e., people’s faces) and nonsocial (inanimate objects). The percentage of time children spent looking at the two types of stimuli was recorded (ranging from 0 to 100). Consider the graphs shown for a study about blaming the victim. a. What is proper statistical the notation of the design? Use the “__ × __” format. b. Interpret the graphs for the blaming the victim study. For each graph, what are the significant main effects? Is there an interaction? Interpret the main effects and interactions that are present.arrow_forward
- Linear Algebra: A Modern IntroductionAlgebraISBN:9781285463247Author:David PoolePublisher:Cengage LearningFunctions and Change: A Modeling Approach to Coll...AlgebraISBN:9781337111348Author:Bruce Crauder, Benny Evans, Alan NoellPublisher:Cengage LearningGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill