Dentists’ use of anesthetics. Refer to the Current Allergy &

Dentists’ use of anesthetics. Refer to the Current Allergy & Clinical Immunology (March 2004) study of allergic reactions of dental patients to local anesthetics, presented in Exercise 2.99 (p. 72). The study reported that the mean number of units (ampoules) of local anesthetics used per week by dentists was 79, with a standard deviation of 23. Consider a random sample of 100 dentists, and let  represent the mean number of units of local anesthetic used per week for the sample.
Exercise 2.99
Dentists’ use of anesthetics. A study published in Current Allergy & Clinical Immunology (Mar. 2004) investigated allergic reactions of dental patients to local anesthetics. Based on a survey of dental practitioners, the study reported that the mean number of units (ampoules) of local anesthetics used per week by dentists was 79, with a standard deviation of 23. Suppose we want to determine the percentage of dentists who use less than 102 units of local anesthetics per week.
a. Assuming that nothing is known about the shape of the distribution for the data, what percentage of dentists use less than 102 units of local anesthetics per week?
b. Assuming that the data has a mound-shaped distribution, what percentage of dentists use less than 102 units of local anesthetics per week?