7. when companies employ control charts to monitor the quality of their products, a series of small samples is typically used to determine if the process is "in control" during the period of time in which each sample is selected. suppose a concrete-block manufacturer samples nine blocks per hour and tests the breaking strength of each. during one-hour’s test, the mean and standard deviation are 985.6 pounds per square inch (psi) and 22.9 psi, respectively. a. construct a 99% confidence interval for the mean breaking strength of blocks produced

A 99% confidence interval for the mean breaking strength of blocks produced is

Step-by-step explanation:

A (1 - )x100% confidence interval for the average break in these conditions It is an interval for the population mean with unknown variance and is given by:

With this information the interval is determined by:

heudhduxhdnshenebdutbbt

step-by-step explanation:

hrhhdhdbbrurb ees

step-by-step explanation:

points a and b are equidistant from the desired line, so the line you find by using them will go through point r.

using points other than a and b will give the desired line only if they are equidistant from r. if they are randomly located, the perpendicular line you create will not necessarily go through point r, hence will not be a solution to the problem.