Hello, I need some help. There is a file attached. This should be done with quality!

Do you require help with your paper? Use our custom writing service to achieve better grades and meet your deadlines. Trust our team of writing experts with your work today, and enjoy peace of mind.


Order a Similar Paper Order a Different Paper

Hello, I need some help. There is a file attached. This should be done with quality!

Hello, I need some help. There is a file attached. This should be done with quality!
Periwinkle Shell Variability – Descriptive Statistics & Histograms (10 pts)   The periwinkle is a small (ca. 1 cm long) marine snail that lives in the intertidal zone in New England.  In 1982 and 1983 biologist Robin Seeley collected and measured shells of snails she collected in the Cape Cod area. She also measured museum specimens collected pre-1900 Cod.  Her data are given in Table 1. Table 1. Shell thickness, in millimeters, of periwinkles collected near Cape Cod, MA. Shell thickness was measured with a caliper. Snails were collected directly from the littoral zone in 1982 and 1983. Data from pre-1900 were obtained from snails in museum collections. Sample # Pre-1900 1982-1983 14 11 14 14 15 11 11 10 12 10 13 13 11 12 12 12 13 14 14 13 15 14 16 14 17 13 18 10 19 10 20 10 15 21 12 22 13 23 11 15 24 12 16 25 17 26 16 27 12 28 18 29 16 30 15 31 15 32 13 33 15 34 11 35 17 Mean Descriptive Statistics: We can use a variety of statistics to summarize our data including range, mean (average), and median. Complete the following data table. Table 2. Summary of descriptive statistics comparing shell thickness (in millimeters) of periwinkles collected prior to 1900 and during 1982 & 1983. Statistic Pre-1900 1982-1983 Range (mm) Median (mm) Mean (mm) Histograms: A particularly good way to represent variation in a population is to use a histogram or frequency distribution which plots number of observations in a given category vs. category. Perhaps the biggest trick in creating a histogram is selecting the size of the categories (bins) – too few or too many will provide less information. In this case, we will make it simple by creating a histogram with bins of 2mm increments. Complete Table 3 by adding up the number of observations in each of the categories for each population. Table 3. Frequency distribution of shell thickness for periwinkles collected pre-1900 and in 1982-1983 near Cape Cod, MA. Shell Thickness Category (mm) Number of Observations Pre-1900 1982-1983 0 – 1.9 2.0 – 3.9 4.0 – 5.9 6.0 – 7.9 8.0 – 9.9 10.0 – 11.9 12.0 – 13.9 14.0 – 15.9 16.0 – 17.9 18 – 19.9 Now, label the Y axis “number of observations” and label the X axis appropriately. Then plot the data. Darken in the bars for each. The figure should have an appropriate figure legend underneath the figure with figure number and an indication of what this graph shows, with appropriate units. Summary Question: What conclusions about the periwinkles do you draw from the graphs?  Pre – 1900 population                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 1982-3 population                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  

Writerbay.net

Our writing experts are ready and waiting to assist with any writing project you may have. From simple essays, research papers, lab reports, and dissertations, to online classes, you can be sure we have a service that perfectly matches your needs.


Order a Similar Paper Order a Different Paper