A reading X taken from a chemical process is know to be a normal random Variable with a mean of 4.0 gm and with 8% of the readings exceeding 4.2 gm. Assume it is possible to adjust the scales in a linear manner to read Y = aX+b. How should a and b be chosen in order that Y has the same mean but fewer than 2% of the readings of Y exceed 4.2 gm