1 The total project cost for a Trex deck ranges between $1,500 and $2,200 for a 250sf deck. 2  Trex Select of basic quality averages approximately $7/sf.  Trex Enhance of higher quality is approximately $8/sf.
When the hypothesized value is zero then there is a simple relationship between hypothesis testing and confidence intervals: If the interval contains zero then the null hypothesis cannot be rejected at the stated level of confidence. If the interval does not contain zero then the null hypothesis can be rejected.
Using a right tail test and alpha = 0.05 the critical t is: 2.13. Since the test statistic (1.98) lies to the left of the critical t (2.13), we fail to reject the null hypothesis that the difference between pre-test score and post-test score is zero.he critical region is the set of z scores that will cause us to reject the null hypothesis. For example if we were doing a two tail test with alpha set at 0.05 the critical region would be determined as shown below.