Consider the following statements regarding the working stress design method:

1. Working stress design is based on the elastic theory.

2. The working stress in the member should be less than the permissible stress.

3. The permissible stress is the ratio of the factor of safety to the yield stress.

4. The permissible stresses for fasteners are usually based on the ultimate strength of the connection.

Which of the above statements is/are not correct?