below is the question sir/ms

3. The mass, in grams, of a packet of biscuits of a particular brand, follows a normal distribution with mean I\" . Six packets of biscuits are chosen at random and their masses noted. The results, in grams, are: 398, 399, 401, 394, 397, and 400. Calculate: a. a 99% condence interval for\" . b. a 98% probability to assert the maximum error