Question

Does anybody know what I am doing wrong? Even got the equation from Excel...

Every few years, the National Assessment of Educational Frogress asks a national sample of eighth-gracers to perform the same matn tasks. The g0 is to get an honest picture of progress in mธ廿. Suppose these are the last few national mean scores, on scale cr u to SOD. 2013 rear Score 265 200 280 285 287 (a] Make a time plot of the meer scores, by hand. This is Just scatterpict at score against year. There s a slow linear increasing trend. Score Score 250 enr 2020 2010 Score "2309· 010 20: Tear ◇1990 2000 2010 b] Find the re placs.) ress en Ine of mean score on time ste ste2. F rst Calculate che mean a d standerd de iation of each v able and the r con elaton us스 a calculator with these functions . Then nnd the e uation of the least s ares line cm these Round Your ansxers to two dedma aw the line on Your scatterpot, whet percent of the year-to-year vanaucnn scores is explained by the linear trend? Round your arswer to ore decimal pao 嚣

Answer 1

Using Excel we get, regression equation is,

$\hat y = -1556.55 + 0.9154 x$