It is generally accepted that if the Engel's coefficient is not greater than 0.3, it can be regarded as entering the well-off level. The monthly per capita income of the region from 2004 to 2008 is 706 yuan, 782 yuan, 878 yuan, 986 yuan and 1116 yuan in turn. According to this increasing trend, this paper tries to use these data and y = AE ^ BX (a > 0) as the function model to predict which year the region will enter the well-off level In economics, the ratio of family expenditure on diet to total income is called Engel's coefficient, which is one of the data to measure the comprehensive strength of a country or region. The per capita monthly income of a certain region in China is x (100 yuan). According to the statistical data, the Engel's coefficient f (x) = (0.1X + a) / (X-B) (x > 4.2), where a and B are constants, and B ∈ Z. Let f (5) = 0.8,0.55

It is generally accepted that if the Engel's coefficient is not greater than 0.3, it can be regarded as entering the well-off level. The monthly per capita income of the region from 2004 to 2008 is 706 yuan, 782 yuan, 878 yuan, 986 yuan and 1116 yuan in turn. According to this increasing trend, this paper tries to use these data and y = AE ^ BX (a > 0) as the function model to predict which year the region will enter the well-off level In economics, the ratio of family expenditure on diet to total income is called Engel's coefficient, which is one of the data to measure the comprehensive strength of a country or region. The per capita monthly income of a certain region in China is x (100 yuan). According to the statistical data, the Engel's coefficient f (x) = (0.1X + a) / (X-B) (x > 4.2), where a and B are constants, and B ∈ Z. Let f (5) = 0.8,0.55

F (x) = (0.1 x + a) / (X-B) (x > 4.2), where a and B are constants and B ∈ Z. Let f (5) = 0.8,0.55