question the number of newly reported crime cases in a county in new york state is shown in the accompanying…

question the number of newly reported crime cases in a county in new york state is shown in the accompanying table, where x represents the number of years since 2002, and y represents number of new cases. write the linear regression equation that represents this set of data, rounding all coefficients to the nearest hundredth. using this equation, find the projected number of new cases for 2011, rounded to the nearest whole number.\nyears since 2002 (x) new cases (y)\n0 1130\n1 1172\n2 1180\n3 1279\n4 1275

question the number of newly reported crime cases in a county in new york state is shown in the accompanying table, where x represents the number of years since 2002, and y represents number of new cases. write the linear regression equation that represents this set of data, rounding all coefficients to the nearest hundredth. using this equation, find the projected number of new cases for 2011, rounded to the nearest whole number.\nyears since 2002 (x) new cases (y)\n0 1130\n1 1172\n2 1180\n3 1279\n4 1275

Answer

Explanation:

Step1: Calculate sums

Let $n = 5$ (number of data - points). $\sum_{i = 1}^{n}x_i=0 + 1+2 + 3+4=10$ $\sum_{i = 1}^{n}y_i=1130 + 1172+1180+1279+1275 = 5936$ $\sum_{i = 1}^{n}x_i^2=0^2 + 1^2+2^2 + 3^2+4^2=0 + 1+4 + 9+16 = 30$ $\sum_{i = 1}^{n}x_iy_i=0\times1130+1\times1172 + 2\times1180+3\times1279+4\times1275=0 + 1172+2360+3837+5100 = 12469$

Step2: Calculate slope $m$

The formula for the slope $m$ of the regression line is $m=\frac{n\sum_{i = 1}^{n}x_iy_i-\sum_{i = 1}^{n}x_i\sum_{i = 1}^{n}y_i}{n\sum_{i = 1}^{n}x_i^2-(\sum_{i = 1}^{n}x_i)^2}$ $m=\frac{5\times12469-10\times5936}{5\times30 - 10^2}=\frac{62345-59360}{150 - 100}=\frac{2985}{50}=59.70$

Step3: Calculate y - intercept $b$

The formula for the y - intercept $b$ is $b=\frac{\sum_{i = 1}^{n}y_i-m\sum_{i = 1}^{n}x_i}{n}$ $b=\frac{5936-59.7\times10}{5}=\frac{5936 - 597}{5}=\frac{5339}{5}=1067.80$

The linear regression equation is $y = 59.70x+1067.80$

Step4: Find $x$ value for 2011

Since $x$ represents the number of years since 2002, for 2011, $x = 2011 - 2002=9$

Step5: Predict number of new cases

Substitute $x = 9$ into the regression equation: $y=59.70\times9+1067.80=537.3+1067.80 = 1605.1\approx1605$

Answer:

The linear regression equation is $y = 59.70x+1067.80$ and the projected number of new cases for 2011 is 1605.