Let X 1 , X 2 , , X n be a sample from an exponential distribution with parameter . It can be shown that

Let X₁, X₂, …, X_n be a sample from an exponential distribution with parameter λ. It can be shown that 2λ Σⁿ_i=1 X_i has a chi-square distribution with 2n degrees of freedom. Use this fact to devise a test statistic and critical region for H₀: λ = λ₀ versus the three usual alternatives.