Lab 5- Two Sample Tests in Ecology

Based on the Lab instructions (file: Ecology Lab 5 Instructions) and the data obtained in previous labs (file: Ecology=Lab.5 Data) please complete the following :

1. Determine and justify if paired or independent data

First, you must determine whether your data are paired or independent. This will determine which tests are appropriate for your data. Describe your data and provide a justification for why your data are paired or independent.

2. Null and alternative hypotheses

State both your null and alternate hypotheses. Your alternate statistical hypothesis should be related to the hypothesis derived from your research question.

3. Test for normality

This will help you determine whether you need a parametric or non-parametric test. We can determine whether data are normally distributed in Excel by visually examining a frequency distribution of the data. For instructions, see Hand-out 5.1: “Testing for normality in Excel”

4. Choose and justify statistical test

State whether you will use a paired or independent t-test, a Mann-Whitney U test, or a Wilcoxon signed rank test, and why.

5. Perform statistical test

Using hand-outs 5.2 – 5.5, perform your statistical test in Excel Present your data separated into two columns for the two groups being compared. Provide us with your P-value from the Excel analysis, and the level of significance used.

6. Interpret results

Based on your obtained P-value, state whether your data support your null or alternate hypothesis. If you do find a statistical difference between the two groups, examine the means of each group to determine which group had larger or smaller values.

Be so kind to upload the Excel table and the graphs too. Thank you very much