Question

In an investigation that uses the scientific method, which step immediately follows making a hypothesis?

Answer 1

In an investigation that uses the scientific method, which step immediately follows making a hypothesis?
summarizing the results
asking a question
making observations
designing an experiment  -- THIS IS THE ANSWER.

Since we already have a hypothesis, we need to test the hypothesis and this is done by designing an experiment that will do this test.

Answer 2

Answer: designing an experiment

A hypothesis can be defined as the testable statement based on the scientific law or theory which needs to be proved by  appropriate experimental methodology.

According to the given situation, in an investigation that uses the scientific method, which needs to be followed immediately after making a testable hypothesis is designing an experiment, which includes choosing an appropriate technique for collecting a data, and methodology of experimental setup.