According to a 2008 study published by the afl-cio, 78% of union workers had jobs with employer health coverage compared to 51% of nonunion workers. in 2009, the employee benefit research institute cited data from large samples that suggested that 80% of union workers had health coverage compared to 56% of nonunion workers. let’s suppose the 2009 data came from random samples of 3,000 union workers and 5,000 nonunion workers. compute the mean of the sampling distribution of differences in the proportions insured.