A recent study shows that antibiotics added to animal feed to accelerate growth can become airborne. Some of these drugs can be toxic if inhaled and may increase the evolution of antibiotic-resistant bacteria. Scientists analyzed 20 samples of dust particles from animal farms. Tylosin, an antibiotic used in animal feed that is chemically related to erythromycin, showed up in 16 of the samples.

(a) What is the variable in this study? What are the individual cases? (b) Display the results in a frequency table. (c) Make the bar chat of the data. (d) Give a relative frequency table of the data