Composite decking is increasingly popular, as it requires little maintenance. Options include polyethylene (with an average cost per square foot of $7.82), polypropylene (average cost per square foot, $8.68) and polyvinyl chloride or PVC (average cost per square foot, $7.50 hollow core, $9.48 solid core.) Pros. Composite materials are very durable, and won't splinter or rot.
Two-sample t-tests for a difference in mean involve independent samples or unpaired samples. Paired t-tests are a form of blocking, and have greater power than unpaired tests when the paired units are similar with respect to noise factors that are independent of membership in the two groups being compared.
1 Independent variable that is categorical (i.e., two or more groups). 2  Cases that have values on both the dependent and independent variables. 3  Independent samples/groups (i.e., independence of observations). 4  There is no relationship between the subjects in each sample.unning the Test. To run the Independent Samples t Test: 1  Click. 2  Move the variable. 3  to the Grouping Variable field, and move the variable. 4  to the Test Variable(s) area. 5  Now. 6  is defined as the independent variable and. 7  is defined as the dependent variable. 8  Click Define Groups, which opens a new window.