Let X1, X2, ..., Xn (n ≥ 3) be a random sample from the uniform distribution on the interval (θ1 - θ2, θ1 + θ2), where θ1 ∈ R and θ2 > 0 are unknown parameters. Let X(j) be the jth order statistic, and let X̄ be the sample mean. If (X(1), X(n)) is a complete and sufficient statistic for (θ1, θ2), which of the following statements is true?

Let (X1, Y1), (X2, Y2), ..., (X10, Y10) be a random sample from a bivariate normal distribution BVN(μ1, μ2, σ12, σ22, ρ) with μ1=5, μ2=6, σ12=4, σ22=9 and ρ=1/2. Then, which of the following statements is true?