Cadbury's produces a Fruit and Nut chocolate bar which has an advertised weight of 60 grams. The production of chocolate bars involves sequences of physical operations which have some inherent randomness, and it is known that the chocolate bar system produces bars which have an approximately normal distribution with a standard deviation of 2 gm. If the system is set so that the average bar weighs 60 gm., then half of the production will weigh less than 60 gm, and half will weigh more. Assume that North American standards require that, if a company advertises that the weight of a product is 60 gm., that at least 95% of the units produced must weigh at least 60 gm. At what level should the average chocolate bar weight be set to conform to the standard?