Milk cartons are advertised to contain one litre of milk. From a randomly sample of 18 one-litre cartons whose contents were accurately measured by the South African Bureau of Standards (SABS), it was found that the average fill was 0.98 litres with a sample standard deviation of 0.052 litres. Assume that the fill of one-litre milk cartons is normally distributed. i. Using a 99% confidence level, estimate the actual mean fill of all one-litre milk cartons. Interpret your findings and comment on the question. (4) ii. Repeat the exercise in (i) above, but use 90% confidence level. (4) iii. Explain any differences in the findings computed above