cs <- c(23, 19, 30, 22, 23, 29, 35, 36, 33, 25) ts <- c(430, 430, 333, 410, 390, 377, 325, 310, 328, 375) mod <- lm(ts ~ cs) # obtain the SER using `summary()` and save the value to `SER` # compute the SSR and save it to `SSR` # do the comparison # obtain the SER using `summary()` and save the value to `SER` SER <- summary(mod)$sigma # compute the SSR and save it to `SSR` SSR <- SER^2*(length(ts)-2) # do the comparison SSR == sum(mod$residuals^2) test_object("SER") test_object("SSR") test_or({ test_student_typed("SSR == sum(mod$residuals^2)") },{ test_student_typed("sum(mod$residuals^2) == SSR") } ) success_msg("Nice!")