Researchers develop a model to predict the age, y, of the individual based on the gender of the individual ,x1 (0=female, 1= male), the height of the second premolar, x2, the number of teeth with root development, x3, and sum of the normalized heights of seven teeth on the left side of the month, x4. The normalized height of the seven teeth was found by dividing the distance between teeth by the height of the tooth. Their model is shown below. Complete parts (a) through (d).
Y= 9.139 + 0.392x1 + 1.256x2 + 0.678x3 - 0.90x4 - 0.174x3x4
(a) Based on this model, what is the expected age of a female with x2 = 27mm, x3=9, and x4= 16mm? (.........) years.( Round to one decimal place as needed)
(b) Based on this model, what is the expected of a male with x2=27, x3=9 and x4=16mm
(c) What is the interaction term? What variable interact?
(d) The Coefficient of determination for this model is 85.5%. Explain what this means.