The Labor Department recently released a report on job changing patterns in the US. Included in the report were results from a survey of 1000 workers from each of four job classifications. In the sample of 1000 restaurant workers, 260 said they had changed jobs within the past year. In the sample of 1000 construction workers, the number who reported changing jobs was 300. For the remaining two samples— office workers and sales staff— the numbers were 290 and 350, respectively. Test the hypothesis that the proportion of workers who would report changing jobs in the last year is the same for all four populations. Use a significance level of 5%.