Analysis of Ball Gall Dataset and Gall Sizes

Part 1: Ball Gall Dataset and Relative Proportions

Part 1 Ball gallDataset:(Don’t use any of the flower gall Dataset)1.Using thepie chart option in Excel as Figure 1(i.e. use “Insert Chart”),show the relative proportions of the contents for the ball galls. Pool death due to birdsas bird predation, if any(i.e. don’t separate by type of bird predator). Include death due to unknown causes as an additional enemy, if there were galls with no evidence of Eurostaor a predator or parasite. Include a one-sentence caption below the chart (that you copy and paste into your report) and include the percentages of each categoryin that caption2.How big are tallgoldenrods, using means and standard deviations,a.that don’t have ball galls?b.that do have ball galls?3.For the data you used for question 2, use Excel’s t-test function (Formulas,More Functions, Statistical, t-test). A t-test compares two samples and provides a statistic that allows you to conclude whether their meansdiffer statistically. You will have to populate four boxes in the t-test. The first array is one of the datasets

2(e.g. plants without galls). You can use your mouse to indicate the range here (it will be one column). Or, you can type in the data range (e.g. A1:A27). The second array will be the other dataset (e.g. plants with galls). Note that the datasets will not be the same size(there will be more gall-free plants). The third box is whether you want a one-tailed test or a two-tailed test. We will choose a 2-tailed test because we don’t really have an expectation that one sample will be bigger than the other. The plants with galls might be bigger because egg-laying females choose bigger ones. Or, they might be smaller because the gall is costly for the plant. The fourth box is the type of t-test. Here, you choose a number between 1 and 3. If we chose 1, we would have the same individuals in each sample (say before and after some treatment); that is not appropriate here obviously. Types2 and 3are for different individuals, but they differ in how variable the datasets are.If your standard deviations are reasonably similar, choose type 2. If they are wildly different, choose type 3.Providethe P value calculated by Excel. If the P valueis smaller than .05, conclude the two samples do indeed differ; otherwise, conclude there is no difference.In one or two sentences, speculate about why the two samples are, or are not, the same size4.How big are ball galls(by volume), using means and standard deviations,a.that contain Eurosta?b.that contain one of E. gigantea, E. obtusiventris, or M. unicolor? (That is, pool the data for these three predators/parasitoids)5.For the data you used for question 4, use Excel’s t-test function again (see #3 above). Provide the Pvalue calculatedin this manner. If the P valueis smaller than .05, conclude the two samples do indeed differ; otherwise, conclude there is no difference.In one or two sentences, speculate about why the two samples are, or are not, the same size.6.Do plants with ball galls have smaller estimated inflorescence size? Answer using mean and standard deviation.7.What is the plant density in the vicinity of plants that have a ball gall? Here, use the measurement between the two most distant plants in the sample as a diameter, use the formula area = piX radius^2, and accordingly calculate the mean density (plants per cm^2) with standard deviation.8.Is average gall size smaller when there is more than one gall per plant than when there is only one?a.Note: answering this will depend upon our dataset, and whether we have multiple plants with more than one ball gallPart 2Flower gall dataset:(Don’t use any of the ball gall dataset).9.How big are Tall Goldenrods, using means and standard deviations,3a.that don’t have flowergalls?b.that do have flowergalls?10.For the data you used for question 9, use Excel’s t-test function again (see #3 above). Provide the P valuecalculatedin this manner. If the Pvalueis smaller than .05, conclude the two samples do indeed differ; otherwise, conclude there is no difference.In one or two sentences, speculate about why the two samples are, or are not, the same size.11.Do plants with flowergalls have smaller estimated inflorescence size? Answer using mean and standard deviation.12.What is the plant density in the vicinity of plants that have a flowergall? Here, use the measurement between the two most distant plants in the sample as a diameter, assume it is a circular sample, use the formula area = piX radius^2, and accordingly calculate the mean density (plants per cm^2) with standard deviation.Threemore tests:13.Compareplant heights from the two datasetsa.Determine height (mean +/-S.D.) of unparasitizedplants from the ball gall dataset.b.Determine the same for unparasitizedplants of the flower gall dataset c.Compare the two using a t-test14.Compare plant densities from the two datasetsa.Determine plant density from the ball galldatasetb.Plant density from the flower gall dataset c.Compare using a t-test15.Compareeffect of parasitism on inflorescence sizea.Determineinflorescence size reduction(or increase)for ball galldataset (i.e. plants with ball galls)b.Determineinflorescence size reduction(or increase)for Flower Gall dataset (i.e. plants with Flower Galls)c.Compare using a t-test