Question

Your answer is partially correct. Try again. Use a computer to develop the equation of the regression model for the following data. Determine the predicted value of y for x1 = 190 and x2 = 7. Y X1 X2 12 174 3 18 281 9 31 1894 28 2028 52 1499 47 188 12 38 215 5 25 155 10 36 167 8 17 135 5 (Round your answers to 2 decimal places.) 25.03 -0.05 The regression equation is: û = L 31.01 The predicted value is: v =

Answer 1

MATLAB Code:

close all
clear
clc

y = [12 18 31 28 52 47 38 25 36 17]';
x1 = [174 281 189 202 149 188 215 155 167 135]';
x2 = [3 9 4 8 9 12 5 10 8 5]';

% To obtain the model y = a0 + a1*x1 + a2*x2,
% we need to solve the system Ac = y,
% where A = [1 x1 x2] and c = [a0 a1 a2]
A = [ones(size(x1)) x1 x2];
c = A\y; % Solve the system
fprintf('Model: y = (%.2f) + (%.2f)*x1 + (%.2f)*x2\n', c)
fprintf('Prediction: y(x1 = 190, x2 = 7) = %.2f\n', c(1) + c(2)*190 + c(3)*7)

Output:

Model: y = (25.86) + (-0.07)*x1 + (2.36)*x2
Prediction: y(x1 = 190, x2 = 7) = 29.38