The percent of soil passing through a sieve is one of several soil properties studied by organizations such as the National Highway Institute. A particular experiement considered the percent of soil passing through a 3/8-inch sieve for soil taken from two separate locations. It is known that the percent of soil passing through the sieve is affected by weather conditions. One measurement on soil taken from each location was made on each of 32 different days. The data are available in SoilDataNhi.txt. Is there evidence that the average percent of soil passing through the sieve is different for the two locations? Use R commands to complete the following parts.
(a) Enter the data in R and use the paired T procedure to conduct the test at level α = 0.05, and construct a 95% CI for the difference of the population means.
(b) Use the signed-rank procedure to repeat part (a). Are the p-values and CIs from the two procedures similar?
(c) Conduct the test and CI using the t.test and wilcox.test commands without the paired=T specification. How do the new p-values and CIs compare to those obtained in parts (a) and (b)?
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