STATISTICS Marco is interested in the number of penguins who live on a particular ice floe. He decides to take an aerial photo of the floe and create a 20 by 20 grid on the photo. He randomly selects 3 cells and counts the number of penguins in each. He then finds the mean number of penguins for those 3 cells. Marco repeats this process for a total of 50 samples and makes a dotplot of the 50 means. This graph is an approximation of:
-stratified random sampling.
-the distribution of sample data.
-the distribution of the population.
-the sampling distribution of means.
-the sampling distribution of proportions.