There are rules of thumb also regarding the Alternative Hypothesis formulation.
- The Alternative Hypothesis *never* contains the '=' (equals) sign as part of its relational operator.
In this example: If it is hypothesized that the average springtime temperature in Hawaii is 72 degrees; Then the Alternative Hypothesis is that Ha: µ ≠ 72 degrees, and the corresponding Null Hypothesis is: Ho: µ = 72 degrees.
The relation '≠' (not equals) is understood to mean simultaneously '<' (less than) and '>' (greater than).
In your consideration, is it easier or harder to reject the null hypothesis when the temperature is "different" than a single number? Why?