Referring to Problem 13.7, if 20 switches are to be tested for 12 hr at an accelerated level of one.

Referring to Problem 13.7, if 20 switches are to be tested
for 12 hr at an accelerated level of one cycle every 15 seconds, how many are
expected to fail at the conclusion of the test period?

Problem 13.7

Testing of an electric starter switch was accelerated from a
normal rate of 5 cycles per hour to an accelerated rate of 1 cycle every 20
seconds. At the accelerated rate, failure times were Weibull with an estimated
shape parameter of 1.8 and an estimated characteristic life of 5000 hours. What
is the reliability of the switch under normal use over a I-year period (24
hours a day)?