8.42 Ammeters produced by a certain company are marketed under the specification that the standard deviation of gauge readings be no larger than 0.2 amp. Ten independent readings on a test circuit of constant current, using one of these ammeters, gave a sample variance of 0.065. Does this suggest that the ammeter used does not meet the company’s specification?

[Hint: Find the approximate probability of a sample variance exceeding 0.065 if the true population variance is 0.04.]