6.32 Tennis Anyone? A stringer of tennis rack- ets has found that the actual string tension achieved for any individual racket stringing will vary as much as 3 kilograms per square centimetre (km/ cm) from the desired tension set on the stringing machine. If the stringer wishes to string at a tension lower than that specified by a customer only 5% of the time, how much above or below the customer's specified tension should the stringer set the string- ing machine? (NOTE: Assume that the distribution of string tensions produced by the stringing machine is normally distributed, with a mean equal to the tension set on the machine and a standard deviation equal to 1 km/cm.)