1. A Teachers' union is on strike for higher wages. The union claims that the mean salary for teachers is at most Birr 8,400 per year. The legislator does not want to reject the union's claim, however, unless the evidence is very strong against it. Assume that salaries follow a normal distribution and the population standard deviation is known to be Birr 3000. A random sample of 64 teachers is obtained, and the sample mean is Birr, 9,400. Test if the state legislator accepts the unions' claim or not at 1% significance level. 1-1-​