3. The manager of a machine shop wishes to estimate the average time an operator needs to complete a simple task. The shop has 98 operators. Eight operators are selected as a simple random sample and timed. The observed results are shown below. Estimate the average time for completion of the task among all operators, and place a bound on the error of estimation. Time (in minutes): 4.2 5.1 7.9 3.8 5.3 4.6 5.1 4.1