The cellphone brands owned by a sample of 20 respondents were: Apple, Samsung, Appel, Nokia, Blackberry, HTC, Apple, Samsung, HTC, LG, Blueberry, Samsung, Samsung, APPLE, Motorola, Apple, Samsun, Apple, Samsung a. Clean these data and identify any irregularities in the data. b. Are there any missing values in this set of 20 respondents? Identify the missing values.