=+36. The following data on distilled alcohol content (%)

for a sample of 35 port wines was extracted from the article “A Method for the Estimation of Alcohol in Fortified Wines Using Hydrometer Baumé and Refractometer Brix” (Amer. J. Enol. Vitic., 2006:

486–490). Each value is an average of two duplicate measurements.

16.35 18.85 16.20 17.75 19.58 17.73 22.75 23.78 23.25 19.08 19.62 19.20 20.05 17.85 19.17 19.48 20.00 19.97 17.48 17.15 19.07 19.90 18.68 18.82 19.03 19.45 19.37 19.20 18.00 19.60 19.33 21.22 19.50 15.30 22.25

a. Determine the value of the IQR.