The values of two types of resistors are normally distributed as follows: Type A: mean: 100 ohms; standard deviation: 2 ohms Type B: mean: 50 ohms; standard deviation: 1.3 ohms

(b)

(a) What tolerances would be permitted for type A if only 0.5% were rejected? 300-ohm resistors are made by connecting together three of the type A resistors, drawn. from the total production. What percentage of the 300-ohm resistors may be expected to have resistances greater than 295 ohms?

(c) Pairs of resistors, one of 100 ohms and one of 50 ohms, drawn from the total production for types A and B respectively, are connected together to make 150-ohm resistors. What percentage of the resulting resistors may be expected to have resistances. in the range 150 ohms to 151.4 ohms? (AEB)