a certain statistic will be used as an unbiased estimator of a parameter. let r represent the sampling distribution of the estimator for samples of size 35, and let s represent the sampling distribution of the estimator for samples of size 15. which of the following must be true about r and s ? responses the expected values of r and s will be equal, and the variability of r will be less than the variability of s. the expected values of r and s will be equal, and the variability of r will be less than the variability of s . the expected values of r and s will be equal, and the variability of r will be equal to the variability of s. the expected values of r and s will be equal, and the variability of r will be equal to the variability of s . the expected values of r and s will be equal, and the variability of r will be greater than the variability of s. the expected values of r and s will be equal, and the variability of r will be greater than the variability of s . the expected value of r will be greater than the expected value of s, and the variability of r will be greater than the variability of s. the expected value of r will be greater than the expected value of s , and the variability of r will be greater than the variability of s . the expected value of r will be greater than the expected value of s, and the variability of r will be less than the variability of s.