An agribusiness performed a regression of wheat yield {bushels per acre} using observations on 27 test plots with four predictors (rainfall, fertilizer. soil acidity, hours of sun]. The standard error was 1.26 bushels. (a) Find the approximate width of a 95% prediction interval for wheat yield. (Round your answer to 2 decimal places.) 9i ii [b] Find the approximate width using the quick rule. {Round your answer to 2 decimal places.) 9i 1