The weights of grade A oranges are normally distributed with mean 200 g and standard deviation 12 g. Determine, correct to two significant figures, the probability that

(a) a grade A orange weighs more than 190 g but less than 210 g

(b) a sample of 4 grade A oranges weighs more than 820 g. The weights of grade B oranges are normally distributed with mean 175 g and standard deviation 9 g. Determine, correct to two significant figures, the probability that

(c) a grade B orange weighs less than a grade A orange,

(d) a sample of 8 grade B oranges weighs more than a sample of seven grade A oranges. (C)