The scientist hypothesized that the mold must be producing a chemical that killed the bacteria. he decided to isolate this substance and test it to see if it would kill bacteria. he transferred the mold to a nutrient broth solution. this solution contained all the materials the mold needed to grow. after the mold grew, he removed it from the nutrient broth and then added the broth to a culture of bacteria. he observed that the bacteria in the culture died. his experiments were later used to develop antibiotics.
were his observations qualitative data or quantitative data?