In an experiment designed to measure the adaptation time, the sample average time for n = 9 inspectors was 6.32 sec. and the sample standard deviation was 1.65 sec. It has previously been assumed that the average adaptation time was 7 sec.
a. Do the data contradict prior belief when the level of significance is 0.1?
b. Construct a 90% confidence interval for population average time. Does it confirm your result in part(a)?
c. State your assumptions.