I performed this exercise with the different states in Mexico and figured I should repeat it with Brazil. The Church does not publish membership totals for each Brazilian state, but taking the population of a state and dividing it by the number of stakes and districts produces an estimate for how large and active the Church is in the state.
Overall around one in every 183 Brazilians is a member of the Church. However, Brazil's states differ in terms of the strength and size of the Church just like everywhere else in the world. For instance, the state of Minas Gerais has over 19 million people, seven stakes and eight districts while the state of Rio Grande do Sul has almost 11 million people, a temple, 21 stakes, and nine districts.
Much missionary work is yet to be done Brazil as a whole, considering there are 440 cities with over 20,000 inhabitants without missionaries assigned to the city or a congregation of the Church. To put that into prospective, Mexico only has 60 such cities which fall under the same category. I am currently calculating how many cities the United States have with over 10,000 inhabitants without a congregation or missionaries (which is looking to be around 50).
Below is a list of different Brazilian States and the population (from 2005) per stake. Stakes are counted as one and districts as 0.5.
Rio Grande do Sul
Rio Grande do Norte
Rio de Janeiro
Mato Grosso do Sul