Answer:
y = -4.2x +34
Explanation:
The differences between adjacent y-values are -4.2 for all data points given, so the data is best modeled by a linear function with a slope of -4.2. The value for x=0 (the y-intercept) will be 4.2 higher than the value for x=1, so will be 34.
Thus the model can be ...
... y = -4.2x + 34
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Comment on the attached graph
The graph shows an attempt to model the data with a quadratic function (the first on your answer list). The result is that the x² coefficient is zero, and the model is the equation of a line (as shown above).