Concept explainers
Delaying Adulthood. The convict surgeonfish is a common tropical reef fish that has been found to delay metamorphosis into adult by extending its larval phase. This delay often leads to enhanced survivorship in the species by increasing the chances of finding suitable habitat. In the paper “Delayed Metamorphosis of a Tropical Reef Fish (Acanthurus triostegus): A Field Experiment” (Marine Ecology Progress Series, Vol. 176, pp. 25–38), M. McCormick published data that he obtained on the larval duration, in days, of 90 convict surgeonfish. The data are given on the WeissStats site. At the 5% significance level, do the data provide sufficient evidence to conclude that the
- a. Employ the Wilcoxon signed-rank test.
- b. Employ the t-test.
- c. Compare your results from parts (a) and (b).
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Introductory Statistics (10th Edition)
- Wing Length. D. Cristol et al. published results of their studies of two subspecies of dark-eyed juncos in the paper “Migratory Dark-Eyed Juncos, Junco hyemalis, Have Better Spatial Memory and Denser Hippocampal Neurons Than Nonmigratory Conspecifics” (Animal Behaviour, Vol. 66, Issue 2, pp. 317–328). One of the subspecies migrates each year, and the other does not migrate. A hypothesis test is to be performed to decide whether the mean wing lengths for the two subspecies (migratory and nonmigratory) are different. a. identify the variable. b. identify the two populations. c. determine the null and alternative hypotheses. d. classify the hypothesis test as two tailed, left tailed, or right tailed.arrow_forwardDelaying Adulthood. In the paper, “Delayed Metamorphosis of a Tropical Reef Fish (Acanthurus triostegus): A Field Experiment” (Marine Ecology Progress Series, Vol. 176, pp. 25–38), M. McCormick studied larval duration of the convict surgeonfish, a common tropical reef fish. This fish has been found to delay metamorphosis into adulthood by extending its larval phase, a delay that often leads to enhanced survivorship in the species by increasing the chances of finding suitable habitat. Duration of the larval phase for convict surgeonfish is normally distributed with mean 53 days and standard deviation 3.4 days. Let x denote larval-phase duration for convict surgeonfish. a. Sketch the normal curve for the variable x. b. Simulate 1500 observations of x. (Note: Users of the TI-83/84 Plus should simulate 750 observations.) c. Approximately what valueswould you expect for the sample mean and sample standard deviation of the 1500 observations? Explain your answers. d. Obtain the sample mean…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_forward
- Clocking the Cheetah. The cheetah (Acinonyx jubatus) is the fastest land mammal and is highly specialized to run down prey. The cheetah often exceeds speeds of 60 mph and, according to the online document “Cheetah Conservation in Southern Africa” (Trade&Environment Database (TED) Case Studies, Vol. 8, No. 2) by J. Urbaniak, the cheetah is capable of speeds up to 72 mph. Following is a frequency histogram for the speeds, in miles per hour, for a sample of 35 cheetahs.arrow_forwarda.State the predictors available in this model.arrow_forwardsection 9.4 #20 working with concepts Curing diabetes: Vertical banded gastroplasty is a surgical procedure that reduces the volume of the stomach in order to produce weight loss. In a recent study, 82 patients with Type 2 diabetes underwent this procedure, and 59 of them experienced a recovery from diabetes. Does this study provide convincing evidence that more than 60% of those with diabetes who undergo this surgery will recover from diabetes? Use the α = 0.05 level of significance.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_forwardA local church is interested in determining how length of residence in the present community relates to church attendance. Using a random sample of 15 individuals, they gathered data on how many times in the previous 5 weeks each individual attended church services. The data are provided below. Length of residence in the community Less than 2 years 2-5 years More than 5 years 0 0 1 1 2 3 3 3 3 4 4 4 4 5 4 Using the 5-step model, determine whether and how church attendance is related to length of residence in the community. Use 5% and 1% levels of statistical significance. What are the assumptions for this problem?arrow_forwardThe article "Time Series Analysis for Construction Productivity Experiments" (T. Abdelhamid and J. Everett, Journal of Construction Engineering and" Management, 1999:87–95) presents a study comparing the effectiveness of a video system that allows a crane operator to see the lifting point while operating the crane with the old system in which the operator relies on hand signals from a tagman. Three different lifts, A, B, and C, were studied. Lift A was of little difficulty, lift B was of moderate difficulty, and lift C was of high difficulty. Each lift was performed several times, both with the new video system and with the old tagman system. The time (in seconds) required to perform each lift was recorded. The following tables present the means, standard deviations, and sample sizes. Low Difficulty Mean Standard Deviation Sample Size Tagman 47.79 2.19 14 Video 47.15 2.65 40 Moderate Difficulty Mean Standard Deviation Sample Size Tagman 69.33 6.26 12 Video 58.50 5.59 24 High Difficulty…arrow_forward
- Define A Competitive-Hunter Model ?arrow_forwardChapter 5, Section 1, Exercise 019 MORE BENEFITS OF EATING ORGANICUsing specific data, we find a significant difference in the proportion of fruit flies surviving after 13 days between those eating organic potatoes and those eating conventional (not organic) potatoes. This exercise asks you to conduct a hypothesis test using additional data. In this case, we are testing H0 : po= pcHa: po > pc where po and pc represent the proportion of fruit flies alive at the end of the given time frame of those eating organic food and those eating conventional food, respectively. Use a 5% significance level.Effect of Organic Bananas After 25 DaysAfter 25 days, the proportion of fruit flies eating organic bananas still alive is 0.42, while the proportion still alive eating conventional bananas is 0.40. The standard error for the difference in proportions is 0.029.What is the value of the test statistic?Round your answer to two decimal places. z= What is the p-value?Round your answer to…arrow_forwardAppalachian Bear Rescue (ABR) is a not-for-profit organization located near the Great Smoky Mountains National Park. ABR's programs include the rehabilitation of orphaned and injured black bears, as well as research and education about Appalachian black bears. ABR provides the most natural environment possible for rehabilitating black bears before their release back into the wild. Recently, Katie Settlage performed a study to learn more about the Appalachian black bear population in the Great Smoky Mountains National Park. She and a team of researchers found 68 black bears in the park and took measurements such as paw size, weight, and shoulder height. The stem-and-leaf plots below show the shoulder heights (in centimeters) of the 40 male and 28 female bears from the study. Shoulder Heights (in cm) of Male Bears Shoulder Heights (in cm) of Female Bears 4 9 Key: 4 9 = 49 Key: 5|0 = 50 5 7 8 9 71 1 2 2 2 2 2 3 3 3 4 4 5 5 6 6 788 8 123 4 4 5 6 79 90 0 3 6 79 7 8 1 2 3 3 3 33 4 6 7 555 5…arrow_forward
- Linear Algebra: A Modern IntroductionAlgebraISBN:9781285463247Author:David PoolePublisher:Cengage Learning