which ethnicities contributes to the country's population?
Mestizos, Yucantan, Quintana Roo, Campeche, Oaxaca etc
Ethnicity and race
Mestizos
the culture of the aztec empire was based around which geographic form Central Mexico this culture became popular between which time period? Post-classic period from 1300 to 1521 which language was spoken by the people of that time? Nahuatl language what was the reason for the population decline during that time? After the arrival of the Europeans in Mexico and the conquest, indigenous populations declined significantly. when did they arrive? 1519–1521 is human sacrificing a part of the culture mentioned above? Yes, death was instrumental in the perpetuation of creation, and gods and humans alike had the responsibility of sacrificing themselves in order to allow life to continue. how is the climate of the above mentioned country? Cooler temperatures during the winter months  in the north while temperatures are fairly constant year round in the south.
The Mixtec and Zapotec peoples, to name a few. Yucatán, Quintana Roo, and Campeche. The earliest complex civilization here was the Olmec culture.
Mexico Mexico Mexico
Ethnicity and race Ethnicity and race Indigenous civilizations
Mexican states such as Yucatán at 59%, Quintana Roo 39% and Campeche 27%, who are chiefly Maya; Oaxaca with 48% of the population, the most numerous groups being the Mixtec and Zapotec peoples; Chiapas at 28%, the majority being Tzeltal and Tzotzil Maya; Hidalgo 24%, the majority being Otomi; Puebla 19%, and Guerrero 17%, mostly Nahua peoples and the states of San Luis Potosí and Veracruz are both home to a population that is 15% indigenous, mostly from the Totonac, Nahua and Teenek (Huastec) groups. All  Nonetheless, all the censuses conclude that the majority of Mexico's indigenous population is concentrated in rural areas of the southern and south-eastern Mexican states such as Yucatán at 59%, Quintana Roo 39% and Campeche 27%, who are chiefly Maya; Oaxaca with 48% of the population, the most numerous groups being the Mixtec and Zapotec peoples; Chiapas at 28%, the majority being Tzeltal and Tzotzil Maya; Hidalgo 24%, the majority being Otomi; Puebla 19%, and Guerrero 17%, mostly Nahua peoples and the states of San Luis Potosí and Veracruz are both home to a population that is 15% indigenous, mostly from the Totonac, Nahua and Teenek (Huastec) groups. The earliest complex civilization in Mexico was the Olmec culture, which flourished on the Gulf Coast from around 1500 BC. Olmec cultural traits diffused through Mexico into other formative-era cultures in Chiapas, Oaxaca and the Valley of Mexico. 
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Mexico [SEP] Ethnicity and race
Despite living in a diverse country, the majority of Mexicans are united under the same national identity. This is the product of an ideology, strongly promoted by Mexican academics and politicians such as Manuel Gamio and José Vasconcelos, known as mestizaje, whose goal was that of Mexico becoming a racially and culturally homogeneous country. In practice, this ideology was reflected in Mexico's national censuses of 1921 and 1930: in the former, approximately 60% of Mexico's population identified as Mestizos, and in the latter, Mexico's government declared that all Mexicans were now Mestizos, for which racial classifications would be dropped in favor of language-based ones in future censuses.