Pipes used in a water distribution network are susceptible to breakage due to a variety of factors. When pipes​ break, engineers must decide whether to repair or replace the broken pipe. A team of...

Pipes used in a water distribution network are susceptible to breakage due to a variety of factors. When pipes​ break, engineers must decide whether to repair or replace the broken pipe. A team of civil engineers estimated the ratio of repair to replacement cost of commercial pipe based on the diameter​ (in millimeters) of the pipe.​(IHS Journal of Hydraulic Engineering​,September​ 2012.) The ratios for a sample of 12 different pipe sizes are listed in the accompanying data table. Assume these data represent a random sample selected from all possible types of commercial pipe. A technology analysis of the data is also given.

a. Locate a 95​% confidence interval for the mean ratio of repair to replacement cost for all commercial pipe on the accompanying technology printout.

Extracted text: Technology Analysis One-Sample T: RATIO Descriptive Statistics Mean StDev SE Mean 95% CI for p 12 8.278 0.996 0.287 (7.645, 8.911) u: mean of RATIO


Extracted text: Data Table 6.584 6.973 7.390 7.779 7.922 8.201 8.420 8.599 8.969 9.310 9.472 9.718