The data in All-Countries include information for all of the countries of the world, but some of the variables have missing data because values weren’t available for some countries. For example, there are values for Energy use in only 136 of the 213 countries (64%). Suppose students select random samples of 20 countries from the list of all countries, and calculate the proportion of countries with non-missing Energy values in each sample.
(a) Find the mean and standard error for the sample proportions of countries with Energy values for these samples.
(b) Is the sample size of 20 in this example sufficient to be confident that a normal distribution is a good model for these sample proportions?
(c) How would your answers to parts (a) and (b) change if we recorded the proportion of countries in each sample that had missing information for Energy?