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.
The evidence is collected in the form of a sample, and the statistician must then decide. There are two possible errors. The statistician could mistakenly reject a true null hypothesis (called a Type I error), or mistakenly accept a false null hypothesis (called a Type II error).The benefit of the doubt goes to the null hypothesis, which is assumed to be true until the evidence seems to indicate otherwise.he level of significance $\alpha$ is the probability of a Type I error. That is, $\alpha$ is the probability of rejecting a true null hypothesis. In our example above, that probability was 5%.