Student solution to writing 1

Sheet3 Sheet2 Sheet1 X Y Scatter Plot X- YEAR The correlation co-efficient is .9971629495 To find the x intercept and explain it. Y=0.0727x-139.26 0=0.0727x-139.26 139.26 = 0.0727x 139.26/.0727 = x intercept is = 1915.543 x y DATA X=YEARS NOTED BY T WITH T=0 IN YEAR 2000. POPULATIONS IN BILLION- Y Make points out of the data. Use a(t,p) coordinate system where t=0 in 200 and p is the world population, in billions. Plot the points on a (t,p) coordinate system. The linear function is P(t) = 0.623t+6.296. The P(t) describes the growth of the population in number of years The slope of P(t) is m=0.0623; this means that the world population is growing a the rate of 0.623 billion(62,000,000) people each ear. Find the value of the population in the yar 2000 P(t) = 0.0623x+6.2961 P(0) = 0.0623(0) + 62961 P(0) = 6.297 In the year 2000, there was approximately 6.297 billion people in the world.. According to the U.S. Census Bureau, the world population in 2000 was 6,081,002,937 Y-POPULATION The coefficient gives this a accuracy rate of 98%. STUDENT WORK The value of r^2 is the correlation co-efficient. In this example, the value if r^2 is .9971629495. 0000.00 0.00 0000.00 0.00 0000.00 0.00 0000.00 0.00 0000.00 0.00 0000.00 0.00 0000.00 0.00 0000.00 0.00 0000.00 0.00 0.00 0000.00 0.00 0000.00 0.00 0000.00 0.00 0000.00 0.00 0000.00 0.00 0000.00 0.00 0000.00 0.00 0.00 0.00 -00.00 0.00 -00.00 0.00 -00.00 0.00 -00.00 0.00 -00.00 0.00 -00.00 0.00 -0.00 0.00 0.00 0.00 0.00 Year Population (Billions) World Population Growth (1950-1999) Year Population (Billions( World Population Growth (1950-1999) YEARS POPULATION IN BILLIONS Linear Regression The closer the value of r^2 is to 1.00 the better the model is. If r^2 = 1.00 it is a perfect fit. If r^2 is in the .95 to .99 it is a good but appx linear fit. Below .90 will usually say it is non linear and try a different type model. NOTE: We used real data from the Census Bureau to test our model for accuracy.