Answer:
Step-by-step explanation:
From the given information:
There are 30 collections of gems, of which 8 are worthless;
Thus, the number of the genuine diamonds = 30 - 8 = 22.
Let X = random variable;
X consider the value as 0 (for 2 worthless stone selection),
X = 1200(1 worthless stone & 1 genuine stone)
X = 2400 (2 genuine stones selected)
However, the numbers of ways of selecting and chosen Gems can be estimated as:
Thus;
To find E(X):
E(X) = (0 × 0.0644) + (1200 × 0.4046) + (2400 × 0.5310)
E(X) = 0 + 485.52 + 1274.4
E(X) = 1759.92