Answer:
IF mold is added to a bacteria culture, THEN the mold will produce a chemical that will kill the bacteria.
Explanation:
A hypothesis is a testable explanation to an observed problem. A possible solution or possible answer given to a question or problem, which can be tested via experimentation is referred to as HYPOTHESIS. The hypothesis is usually written in an IF, THEN format.
According to this question, a scientist (identified to be Fleming) hypothesized that the mold must be producing a chemical that killed the bacteria and tested it by setting up an experiment whose result turned out to support his hypothetical claim.
Therefore, his hypothesis in an IF, THEN statement is:
IF mold is added to a bacteria culture, THEN the mold will produce a chemical that will kill the bacteria.