Analyze the data in the following problems using median and up or down run tests with $z=+-2.$

a$.$ Given the following run test results of process output, what do the results of the run tests suggest about the process?

random

non$-$random

b$.$ Twenty means were plotted on a control chart. An analyst counted $11$ runs above or below the median, and $11$ up or down runs. Wha

do the results suggest about the process?

random

non$-$random

c$.$ The following data are the number of defects per spool of cable.

d$.$ The postmaster of a small western town receives a certain number of complaints each day about mail delivery.