For a relation consisting of (x, y) pairs to be a function, all of the x-values must be unique. In the given relation, points (-2, -3) and (-2, 1) have the same x-value. Removing either point will make the relation a function.
Of these, the only one listed among answer choices is (-2, 1).
The Central Limit Theorem (CLT) implies that the distribution of the mean is approximately normal for large n. I.e. the distribution of the population means will be approximately normally distributed, and provided there is a large sample of the population.
