It is thought that Vitamin C might be an effective preventative for the common cold. You design an experiment to see which
fruit juice has the highest level of Vitamin C. How might a
hypothesis for this experiment be stated?

IF the fruit juice contains a high level of vitamin C, THEN the preventative effectiveness against common cold increases.

Explanation:

The hypothesis is a testable explanation of a scientific investigation. It aims at predicting the outcome of the experiment. One feature of the hypothesis is that it must be testable. The hypothesis is usually written in an "IF, THEN" format.

This question is regarding an experiment to test the amount of vitamin C in fruit juice. The vitamin C is thought to be an effective preventative against common cold. Hence, the hypothesis connects the effect on common cold (dependent variable) with the amount of vitamin C (independent variable). The hypothesis can be written as:

IF the fruit juice contains a high level of vitamin C, THEN the preventative effectiveness against common cold increases.