https://www.youtube.com/watch?v=TtqUCUr711s&list=PLsri7w6p16vsOVj5cL8U4z0m4RdMZfhme&index=3 ================================================================================ Effect of "brand" to "satisfaction" Effect of "region" to "satisfaction" ================================================================================ Even if A and B are independent, A and B can affect "interation effect" to "dependent variable" like satisfaction So, effects are A, B, A+B ================================================================================ 2 independent variables Numbers: satisfaction Question: there is difference in "satisfaction" wrt "2 variables" using $$$\alpha=0.05$$$? ================================================================================ Establish hypothesis $$$\bar{x}$$$: mean of entire $$$\bar{x}_i$$$: mean of each conveninet store $$$\bar{x}_j$$$: mean of each conveninet store's location $$$\bar{x}_{ij}$$$: 2 independent variables $$$\bar{x}_{ijk}$$$: 2 independent variables, kth observation ================================================================================ i: conveninet store A,B,C j: location, KangNam, HongDae, JongRo k: kth satisfaction ================================================================================ ================================================================================ $$$SST = (1-2.926)^2 + (4-2.926)^2 + \cdots + (4-2.926)^2 = 23.862$$$ $$$SSB_i = 9(2.228-2.926)^2 + 9(3.111-2.926)^2 + \cdots + 9(3.444-2.926)^2 = 7.183$$$ $$$SSB_j = 9(3.111-2.926)^2 + 9(2.778-2.926)^2 + \cdots + 9(2.889-2.926)^2 = 0.517$$$ Interaction $$$SSB_{ij} = 3(2.000-2.222-3.111+2.926)^2 + \cdots + 3(3.333-3.444-2.889+2.926)^2 = 1.481$$$ $$$SSW = SST - SSB_i - SSB_j - SSB_{ij} = 14.671$$$ ================================================================================ $$$MSB_i = \dfrac{SSB_i}{i-1} = \dfrac{7.183}{3-1} = 3.592$$$ $$$MSB_i = \dfrac{SSB_j}{j-1} = \dfrac{0.517}{3-1} = 0.259$$$ $$$MSB_{ij} = \dfrac{SSB_{ij}}{(i-1)(j-1)} = \dfrac{1.481}{(3-1)(3-1)} = 0.370$$$ $$$MSW = \dfrac{SSW}{i\times j \times (k-1)} = \dfrac{14.671}{3\times 3 \times 2}=0.815$$$ ================================================================================ ================================================================================