cs <- c(23, 19, 30, 22, 23, 29, 35, 36, 33, 25) ts <- c(430, 430, 333, 410, 390, 377, 325, 310, 328, 375) # compute mean, variance and standard deviation of test scores # compute the covariance and the correlation coefficient # compute mean, variance and standard deviation of test scores mean(ts) sd(ts) var(ts) # compute the covariance and the correlation coefficient cov(ts, cs) cor(ts, cs) test_predefined_objects("cs") test_predefined_objects("ts") test_function("mean", args = "x") test_function("sd", args = "x") test_output_contains("cov(ts,cs)") test_output_contains("cor(ts,cs)")