Atotal of 13,000 sheet metal stampings must be produced in the press department during the next three days. manually operated presses (one operator per press) will be used to complete the job and the cycle time is 27 sec. each press must be set up with a punch-and-die set before production starts. setup time is 2.0 hr, and availability is assumed to be 100%. how many presses and operators must be devoted to this production during the three days, if there are 7.5 hr of available time per machine per day?

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