4. a. Draw the membership functions for the following sets: M: mature people Y: young people O: old people

b. Classify a person who is i. 18 years old ii. 21 years old iii. 42 years old iv. 61 years old

c. Explain how you would defuzzify your answer for part b. iii. above (i.e., obtain the age of 42 from your fuzzy categorization).