brothers in sajha,,,iam taking c++ class n having a hard time with my assignment,,,iam supose to make a program regarding linear regression,,,my teacher send me this help but iam still confused.            any help will be appreciated ,,,plz dont make a funny coments,,iam dam serious right now.                                                                                                                       jai nepal   Regression Tutorial Regression Definition: A regression is a statistical analysis assessing the association between two variables. It is used to find the relationship between two variables. Regression Formula: Regression Equation(y) = a + bx Slope(b) = (NΣXY - (ΣX)(ΣY)) / (NΣX2 - (ΣX)2) Intercept(a) = (ΣY - b(ΣX)) / N where x and y are the variables. b = The slope of the regression line a = The intercept point of the regression line and the y axis. N = Number of values or elements X = First Score Y = Second Score ΣXY = Sum of the product of first and Second Scores ΣX = Sum of First Scores ΣY = Sum of Second Scores ΣX2 = Sum of square First Scores   Regression Example: To find the Simple/Linear Regression of X Values Y Values 60 3.1 61 3.6 62 3.8 63 4 65 4.1 To find regression equation, we will first find slope, intercept and use it to form regression equation.. Step 1: Count the number of values. N = 5 Step 2: Find XY, X2 See the below table X Value Y Value X*Y X*X 60 3.1 60 * 3.1 = 186 60 * 60 = 3600 61 3.6 61 * 3.6 = 219.6 61 * 61 = 3721 62 3.8 62 * 3.8 = 235.6 62 * 62 = 3844 63 4 63 * 4 = 252 63 * 63 = 3969 65 4.1 65 * 4.1 = 266.5 65 * 65 = 4225   Step 3: Find ΣX, ΣY, ΣXY, ΣX2. ΣX = 311 ΣY = 18.6 ΣXY = 1159.7 ΣX2 = 19359 Step 4: Substitute in the above slope formula given. Slope(b) = (NΣXY - (ΣX)(ΣY)) / (NΣX2 - (ΣX)2) = ((5)*(1159.7)-(311)*(18.6))/((5)*(19359)-(311)2) = (5798.5 - 5784.6)/(96795 - 96721) = 13.9/74 = 0.19 Step 5: Now, again substitute in the above intercept formula given. Intercept(a) = (ΣY - b(ΣX)) / N = (18.6 - 0.19(311))/5 = (18.6 - 59.09)/5 = -40.49/5 = -8.098 Step 6: Then substitute these values in regression equation formula Regression Equation(y) = a + bx = -8.098 + 0.19x. Suppose if we want to know the approximate y value for the variable x = 64. Then we can substitute the value in the above equation. Regression Equation(y) = a + bx = -8.098 + 0.19(64). = -8.098 + 12.16 = 4.06 This example will guide you to find the relationship between two variables by calculating the Regression from the above steps.