Soil ph is an important variable in the design of structures that will contact the soil. nine test samples of soil from a potential construction site gave readings of
7.3 6.5 6.4 6.1 6.0 6.5 6.2 5.8 6.7
assuming that soil ph is normally distributed, find the 90% lower confidence bound for the true average soil ph at the site.

90% lower confidence bound for the true average soil pH at the site is ≈ 6.13

Step-by-step explanation:

90% Lower Confidence bound can be calculated using M-ME where

And margin of error (ME)  can be calculated using the formula

ME= where

Using the numbers we get:

ME= ≈ 0.26

Then the 90% lower confidence bound for the true average soil pH at the site is 6.39 - 0.26 = 6.13

true !

step-by-step explanation: