Watches and bacteria: A group of researchers investigated the contamination of medical personnel watches at a New York hospital, since there is a potential for patient exposure to potentially dangerous bacteria. They sampled watches worn by physicians, physician assistants, and medical students at a teaching hospital in New York. Nearly half (46.6%) of the watches tested harbored microorganisms that can cause illness. By comparison, only one of the 10 watches worn by security guards tested positive for a disease-carrying microorganism. The researchers want to determine if the difference is statistically significant.
Which of the following is an appropriate statement of the null hypothesis, H0?
A. The proportion of contaminated wrist-watches from medical personnel is the same as the proportion of contaminated wrist-watches from security guards, i. e., H0: p = 46.6%.
B. The proportion of contaminated wrist-watches from medical personnel is not the same as the proportion of contaminated wrist-watches from security guards, i. e., H0: p not equal 46.6%.
C. The proportion of contaminated wrist-watches from medical personnel is greater than the proportion of contaminated wrist-watches from security guards, i. e., H0: p > 46.6%.