PRECALCULUS 2011-2012: April 2012

Sunday, April 22, 2012

Chapter 2 Project

The current Zestimate price of the house I am living in is $273,300. My grandpa first bought this house in 1988 for $152,000.

Linear Equation : y = -22466.67x + 551066.67

r² = .4484

Quadratic Equation : y = -6886.36x² + 53283.33x + 399566.67

r² = .7181

Cubic Equation : y = 2430.85x³ - 466995.338x² + 238270.78 + 191000

r² = .9146

Quartic Equation : y = 110.72x⁴ - 5.05x³ - 29168.99x² + 189552.84x + 229000

r² = .9168

By looking at the four different equations, the quartic equation has the strongest linear correlation because it is closer to 1. The average yearly appreciation of the house would be $6,217.39 per year. In about 20 years, the price of my current house would be $100,000. Any negative events that will happen in the neighborhood could affect the value of the house since nobody would want to live in a dangerous and unsafe area.

Tuesday, April 17, 2012

CH2 Project

According to the information from zillow.com, the home I live in now is worth $233,000 when I first move in at June in 2009. To find the model, I type in the years for X in the calculator STAT table with 2002 as year 1, 2003 as year 2 and so on; then I put the past values from 2002 through 2011 in thousands of dollars as Y. Next I turn STAT Plot and Diagnostic on, so now I could try applying different regressions with my data from zillow.com. It turn out that quartic regression model,y=.5304487179x^4 - 10.26330614x^3 + 55.10678904x^2 - 63.99339549x +308.9166667, fit the most because coefficient of determination (r^2) is 0.8886096037, which is closer to 1 than the other. To see the graph I set the window to [0,11] by [0,500]. I put in y=100 to find out when will the value be 100,000 but the model did not intersect with the line y=100 with the minimum value $192510.60 at x=9.2 (2010).
In my opinion, the prediction from the quartic model could be change if the government lower the number of immigrants from entering U.S. in the future.If that happen oakland house values will drop from the decreasing demands of rent housing.