Your Textbook Extends the Simple Regression Analysis of Chapters 4 $\widehat { \text { TestScore } } = 698.9 - 2.28 \times \text { STR }$

question 17

Essay

Your textbook extends the simple regression analysis of Chapters 4 and 5 by adding an
additional explanatory variable, the percent of English learners in school districts (PctEl).
The results are as follows: $\widehat { \text { TestScore } } = 698.9 - 2.28 \times \text { STR }$
$\text {and}$
$\widehat { \text { TestScore } } = 686.0 - 1.10 \times S T R - 0.65 \times \text { PctEL }$ Explain why you think the coefficient on the student-teacher ratio has changed so
dramatically (been more than halved).

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Definitions:

Protein-Energy Malnutrition

A serious health condition resulting from a lack of dietary protein and calories, leading to body wasting and susceptibility to infections.

Neuron's Cell Body

the part of a neuron that contains the nucleus and most of the cell's organelles, serving as the processing area for neuronal signals.

Canalization

A concept in developmental biology and psychology, meaning the tendency of heredity to restrict the development of some characteristics to just one or a few outcomes, regardless of environmental variations.

Genetically Determined Growth

Genetically determined growth refers to the influence of genes on the physical development and growth patterns of an organism, including humans.