Refer to the Current Allergy & Clinical Immunology study of the use of local anesthetics in dentistry, presented in Exercise. Recall 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 dentist who used 175 units of local anesthetics in a week.
a. Find the z -score for this measurement.
b. Would you consider the measurement to be an outlier? Explain.