78.5/100 as a decimal is just 0.78.5 and as a percent it is 78.5 %
Words that came from the same ancestral language and originated from the same word are called COGNATE WORDS.
In linguistics, cognates are words that have a common etymological origin. These are words in two languages that share a similar meaning, spelling, and pronunciation. For an instance, English words have lots of related words in Spanish.
The Olmecs (/ˈɒlmɛks, ˈoʊl-/) were the earliest known major civilization in Mesoamerica following a progressive development in Soconusco. They lived in the tropical lowlands of south-central Mexico, in the present-day states of Veracruz and Tabasco. It has been speculated that the Olmecs derive in part from neighboring Mokaya or Mixe–Zoque.