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436    8. Tests of Hypotheses

                                    8.4.12 Suppose that  X , ...,  X  are iid random variables having the
                                                        1
                                                               n
                                 Bernoulli(p) distribution where p ∈ (0, 1) is the unknown parameter. With
                                 preassigned α ∈ (0, 1), derive the randomized UMP level α test for H  : p = p 0
                                                                                           0
                                 versus H  : p > p  where p  is a number between 0 and 1.
                                         1     0       0
                                    8.4.13 Suppose that X , ..., X  are iid random variables having the Poisson(λ)
                                                           n
                                                      1
                                 distribution where λ ∈ ℜ  is the unknown parameter. With preassigned α ∈
                                                       +
                                 (0, 1), derive the randomized UMP level α test for H  : λ = λ  versus H  : λ <
                                                                             0
                                                                                    0
                                                                                             1
                                 λ  where λ  is a positive number.
                                          0
                                  0
                                    8.4.14 Suppose that X , ..., X  are iid having the Uniform(–θ, θ) distribu-
                                                      1
                                                            n
                                 tion with unknown θ(> 0). In order to choose between the two hypotheses H 0
                                 : θ ≤ θ  versus H  : θ > θ  where θ  is a positive number, suppose that we
                                       0
                                                1
                                                                0
                                                       0
                                 reject H  if and only if | X n:n  | > c where c is a fixed known positive number. Is
                                        0
                                 there any α ∈ (0, 1) for which this test is UMP level α?
                                    8.4.15 Suppose that X , ..., X  are iid Geometric(p) where p ∈ (0, 1) is the
                                                      1
                                                            n
                                 unknown parameter. With preassigned α ∈ (0, 1), derive the randomized UMP
                                 level α test for H  : p ≥ p  versus H  : p < p  where p  is a number between 0
                                                                             0
                                                                      0
                                                               1
                                                0
                                                      0
                                 and 1.
                                    8.4.16 Let X , ..., X  be iid having the Rayleigh distribution with the com-
                                              1
                                                    n
                                 mon pdf f(x; θ) = 2θ xexp(–x /θ)I(x > 0) where θ(> 0) is the unknown pa-
                                                   –1
                                                           2
                                 rameter. With preassigned α ∈ (0, 1), derive the UMP level α test for H  : θ ≤
                                                                                             0
                                 θ  versus H  : θ > θ  where θ  is a positive number, in the simplest implementable
                                          1
                                  0
                                                        0
                                                0
                                 form.
                                     (i)  Use the Neyman-Pearson approach;
                                     (ii)  Use the MLR approach.
                                    8.4.17 Let X , ..., X  be iid having the Weibull distribution with the com-
                                                    n
                                              1
                                 mon pdf f(x; a) = a bx exp(-x /a)I(x > 0) where a(> 0) is an unknown
                                                             b
                                                   -1
                                                      b-1
                                 parameter but b(> 0) is assumed known. With preassigned a ∈ (0, 1), derive
                                 the UMP level a test for H  : a ≤ a  versus H  : a > a  where a  is a positive
                                                               0
                                                                                      0
                                                                       1
                                                                              0
                                                        0
                                 number, in the simplest implementable form.
                                     (i)  Use the Neyman-Pearson approach;
                                     (ii)  Use the MLR approach.
                                    8.4.18 (Exercise 8.4.5 Continued) Let X , ..., X  be iid having the common
                                                                           n
                                                                     1
                                                               –1
                                 negative exponential pdf f(x; µ) = σ exp{-(x - µ)/σ}I(x > µ) where µ(∈ ℜ) is
                                 an unknown parameter but σ(∈ ℜ ) is assumed known. With preassigned α ∈
                                                             +
                                 (0, 1), derive the UMP level α test for H  : µ ≤ µ  versus H  : µ > µ  where µ 0
                                                                                  1
                                                                          0
                                                                   0
                                                                                         0
                                 is a real number, in the simplest implementable form.
                                    8.4.19 (Exercise 8.4.1 Continued) Let X , ..., X  be iid having the common
                                                                     1
                                                                           n
                                 Laplace pdf f(x; b) = ½b exp(– | x – a | /b)I(x ∈ ℜ) where b(> 0) is an
                                                       -1
                                 unknown parameter but a(∈ ℜ) is assumed known. With preassigned
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