Let the mean and variance of 7 observations 2, 4, 10, x, 12, 14, y, where x>y, be 8 and 16 respectively. Two numbers are chosen from \(\{1, 2, 3, x-4, y, 5\}\) one after another without replacement, then the probability, that the smaller number among the two chosen numbers is less than 4, is:
If the mean and the variance of the data 
are $\mu$ and 19 respectively, then the value of $\lambda + \mu$ is
Reciprocal levelling is performed for points P and Q by placing the same levelling instrument at A and B. The observations of staff readings are tabulated as below. 
If the Reduced Level (RL) of P is 115.246 m, then the true RL of Q, in m, is _______ (rounded off to 3 decimal places)
The information of a mining project for a life of three years is given below:
Additional data: Applicable tax rate = 30%
Discount rate = 10%
Depreciation method: Straight line with zero salvage value
Data from a borehole log with collar elevation at 590 mRL are given below. Composite grade is calculated using cores of 5 m above and below the reference bench at 580 mRL. The composite grade, in %, is: