A biologist wants to test the null hypothesis that the mean wingspan of a certain kind of insect is 12.3 mm against the alternative that it is not 12.3 mm. If she takes a random sample and decides to accept the null hypothesis if and only if the mean of the sample falls between 12.0 mm and 12.6 mm, what decision will she make if she gets 
= 12.9 mm and will it be in error if
