# verify that the alternative estimator is unbiased n <- 100 w <- c(rep((1+0.5)/n, n/2), rep((1-0.5)/n, n/2)) # define the alternative estimator mu_tilde # compute repeatedly estimates for both estimators and store the results in est_bar and est_tilde set.seed(123) # compute the sample variances for est_bar and est_tilde # verify that the alternative estimator is unbiased n <- 100 w <- c(rep((1+0.5)/n, n/2), rep((1-0.5)/n, n/2)) sum(w) # define the alternative estimator mu_tilde mu_tilde <- function(x){sum(w*x)} # compute repeatedly estimates for both estimators and store the results in est_bar and est_tilde set.seed(123) est_bar <- replicate(expr = mean(rnorm(100, 5, 10)), n = 10000) est_tilde <- replicate(expr = mu_tilde(rnorm(100, 5, 10)), n = 10000) # compute the sample variances for est_bar and est_tilde var(est_bar) var(est_tilde) test_function_result("sum") test_function_definition("mu_tilde", function_test = { test_expression_result("mu_tilde(1:100)") test_expression_result("mu_tilde(2:101)") }) test_object("est_bar") test_object("est_tilde") test_function_result("var", index = 1) test_function_result("var", index = 2) success_msg("Correct! The sample mean is more efficient (that is, has a lower variance) than the alternative estimator.")