A researcher is interested in levels of job satisfaction among manual workers in a firm that is undergoing change. The firm has 1200 manual workers. The researcher selects a simple random sample of 10 per cent of the population. He measures job satisfaction on a Likert scale comprising ten items. A high level of satisfaction is scored 5 and a low level is scored 1. The mean job satisfaction score is 34.3. The standard error of the mean is 8.57. What is the 95 per cent confidence interval?