Question: Health-care workers who use latex gloves with glove powder on a daily basis are particularly susceptible to developing a latex allergy. Symptoms of a latex allergy include conjunctivitis, hand eczema, nasal congestion, a skin rash, and shortness of breath. Each individual in a sample of 46 hospital employees who were diagnosed with latex allergy (based on a skin-prick test) reported on their exposure to latex gloves. (Current Allergy & Clinical Immunology, March 2004) Summary statistics for the number of latex gloves used per week are: sample mean = 19.3 and s = 11.9.

(a) Form a 99% confidence interval for the average number of latex gloves used per week by all health-care workers with a latex allergy.

(b) Give a practical interpretation of the interval you found in part a.