Question

3. (20 points) The following values represent numerical summaries from a random sample of 9 Louisiana parishes where the explanatory variable is number of COVID-19 cases and the response variable is number of COVID-19 deaths (snapshot on April 26, 2020): Ex-2792 Ey-181 Ex-1,384,108 Ey? - 7163 Exy=97,563 Use this information to answer the following questions: LA COVID-19 Number of Death Cases a) Calculate the correlation coefficient between the number of deaths and the number of COVID-19 cases. 100 400 600 800 b) Calculate and write the regression equation for this data. c) Draw the line of best fit on the scatterplot above. Be sure to include calculations for at least two points to draw the line. d) What percent of the variation in the number of deaths from COVID-19 is left unexplained by regression the number of cases?

Answer 1

Date Page Solution Given Ex=2792, Ey = 181, Ex² = 1,384, los Ey² = 7163 , Exy = 97,563 , n = 9 (a) correlation coefficient is calculated as r = Sxo √5xx Syy where Sxx = Ex² - (Ex)² 1384108 - (2792 )? = 517,967.56 - 7163 - (181)2 = 3,522.89 szy - Exy - (Ex) (EN) = 97,563 – (2292)(181) = 41, 412.78 41,412.78 517,967.56x3, 522.89 0.96947. 9 =

Date Page lb The regression equation is given as: ŷ = ât 8x where å = ğ - Ê and ß - szy - 41,412.78 = 0.079952 Sxa S17,967.56 ♡ - 34 - Å ( (19) - 0.079952 ( 2392) ä = -4.69192 The regression equation is : = - 4.69192 + 0.079952