After 3 days of sending my paper to the reviewers by the editor i have a new status saying that "New reviews have been submitted and are being considered by the editor". and 1/4 Assigned reviews completed. what does this mean? is this mean that the edior will make a decision based only on one review?
My reading of that message is simply that one of the four requested reviews has been completed, and that the editor will have a look at it. They might have to follow up with the reviewer (e.g. asking for clarification), or decide to invite an additional reviewer. In most cases the editor won't make a decision until they receive more reports, but it could happen in certain circumstances. So expect to wait a while longer.