Acarpenter charges $30 per hour for up to eight hours each day and increases this rate by 50% for additional hours. the carpenter will not work more than ten hours per day. if this daily cost function is modeled by y = f(x) and graphed, which statement is not correct?
a) f(0) = 0, f(8) = 240, and f(10) = 330.
b) the domain is [0, 10] and the range is [0, 330].
c) the graph is increasing on the interval (8, 10) with a slope of 45.
d) if a $20 trip charge is added, the new x-intercept will be (20, 0).

Farmers know that driving heavy equipment on wet soil compresses the soil and injures future crops. here are data on the "penetrability" of the same type of soil at two levels of compression. penetrability is a measure of how much resistance plant roots will meet when they try to grow through the soil. compressed soil 2.85 2.66 3 2.82 2.76 2.81 2.78 3.08 2.94 2.86 3.08 2.82 2.78 2.98 3.00 2.78 2.96 2.90 3.18 3.16 intermediate soil 3.17 3.37 3.1 3.40 3.38 3.14 3.18 3.26 2.96 3.02 3.54 3.36 3.18 3.12 3.86 2.92 3.46 3.44 3.62 4.26 use the data, omitting the high outlier, to give a 95% confidence interval for the decrease in penetrability of compressed soil relative to intermediate soil. compute degrees of freedom using the conservative method. interval: to