According to the Centers for Disease Control, about 18% of adolescents age 12-19 are obese. Suppose we take a random sample of 3
0 adolescents and find the proportion in our sample who are obese. We record this value. Now, repeat this many more times so that we have a great many sample proportions drawn from this population. Suppose we make a dotplot of the sample proportions. Would the dotplot be a visualization of the population distribution, the distribution of a sample, or the sampling distribution of proportions?
A sample is a small group of observations which is a subset of a larger population containing the entire set of observations. The proportion of success or measure of a certain statistic from the sample, (in the scenario above, the proportion of obese observations on our sample) gives us the sample proportion. Repeated measurement of the sample proportion of this sample whose size is large enough (usually greater Than 30) in other to obtain a range of different proportions for the sample is called the sampling distribution of proportion. Hence, creating a visual plot such as a dot plot of these repeated measurement of the proportion of obese observations gives the sampling distribution of proportions
