Is the decimal equivalent of 27' 9?

Answer 1

27' 9 is a measurement of some unspecified nature: it could be feet and inches or minutes and seconds (of time or degrees). Who knows? You know but you are not telling! Since there are 12 inches in a foot, and 60 seconds in a minute, the conversion from the minor unit (for the 9 in the question) to the major unit (for 27') is unknown. It is, therefore impossible to answer the question.