It is claimed that the average salary for managers in a particular company is $54,000. The standard deviation of that salary is known to be $2,000. A sample of 100 managers is selected and a sample mean of $56,000 is derived. If the goal is to test whether the average salary for managers is greater than $54,000, what is the value of the critical test statistic at the 10% level of significance?
a. z = 1.280
b. z = 1.645
c. t = 1.290
d. t = 1.660