The Mean Gross Annual Incomes of Certified Welders Are Normally $\pi$

Multiple Choice

The mean gross annual incomes of certified welders are normally distributed with the mean of $20,000 and a standard deviation of $2,000.The ship building association wishes to find out whether their welders earn more or less than $20,000 annually.The alternate hypothesis is that the mean is not $20,000.Which of the following is the alternate hypothesis?

A) $\pi$ $\neq$ $20,000
B) µ $\neq$ $20,000
C) µ < $20,000
D) µ = $20,000
E) $\pi$ = $20,000