QUESTION FOUR (20 MARKS)
The mass of a standard loaf of white bread is, by law meant to be 700 g. The MN Bakery, which supplies outlets throughout the Eastern Cape, regularly checks the masses of its standard loaf of bread white bread. If their bread is underweight, on average, they are liable for a fine by the provincial Department of Health, whose inspectors undertake random checks; if the bread is overweight, on average, the bakery is wasting its ingredients. On a given day, a random sample of 81 loaves is selected and weighed. The sample mean mass was found to be 690 g with a population standard deviation of 21 g. Assume that the mass of bread is approximately normally distributed. Is MN Bakery complying with the provincial government regulations, while also not wasting its own resources? Conduct a hypothesis test for a single mean at 10% significance level. What statistical and management conclusions can be drawn. (20)