The prediction equation for predicting y (pain indicator) from X (drug dosage) is y = 2.5X + 18. What is the observation mean for Y if ìX = 40 and óx square = 81?
To calculate the observation mean for Y, you need to substitute the given value of ìX (mean of X) into the prediction equation and solve for the predicted value of Y.
Given:
Prediction equation: y = 2.5X + 18
ìX (mean of X) = 40
óx square (variance of X) = 81
Substitute ìX = 40 into the prediction equation:
y = 2.5(40) + 18
y = 100 + 18
y = 118
Therefore, the observation mean for Y, when ìX = 40, is 118.