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 P-value is the observed significance level of the test. If the observed significance level is less than the chosen significance level (alpha), then the researcher should reject the null hypothesis in favor of the alternative. Otherwise, there is not enough evidence to reject the null hypothesis.