9.2.6 A random sample of $n = 15$ is tested and $\bar{x} = 2.78$. It is known that $\sigma = 0.9$ and that $X$ is normally distributed. a. Test $h_0: \mu = 3$ versus $h_1: \mu \neq 3$ using $\alpha = 0.05$. b. What is the power of this test if $\mu = 3.25$? c. What sample size would be required to detect a true mean of 3.75 if we wanted the power to be at least 0.9?
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Step 1: The null hypothesis is $H_0: \mu = 3$ and the alternative hypothesis is $H_1: \mu \neq 3$. Show more…
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Consider the distributions N(μx, 400) and N(μy, 225). Let θ = μx - μy. Let ˉx and ˉy denote the observed means of two independent random samples each of size n from the respective distributions. Suppose we reject Ho: θ = 0 in favor of Hi: θ > 0 at level α = 0.05. Let K(θ) be the power function of the test. Find n and c so that K(θ) = 0.05 and K(θ = 10) ≥ 0.90. In other words, find n and c such that the test has a significance level of α = 0.05, with power at least 0.90 when the true mean difference is 10.
Sri K.
In order to test a hypothesis Ho: μ=5 Ha: μ<5, a sample of subjects was randomly selected. Suppose the population is Normal with σ=0.92 mg/l. a) Compute the power of the test (α=0.05) if the sample size is 45 and the true mean is 4.75. b) Compute the power of the test (α=0.05) if the sample size is 60 and the true mean is 4.75. c) Compute the power of the test if α=0.1 if the sample size is 45 and the true mean is 4.75. Please show your work.
Consider the distributions 𝑁(𝜇𝑋, 400) and 𝑁(𝜇𝑌, 225). Let 𝜃 = 𝜇𝑋 − 𝜇𝑌. Say 𝑥̅and 𝑦̅ denote the observed means of two independent random samples, each of size n, from the respective distributions. Say we reject 𝐻0: 𝜃 = 0 and retain 𝐻1: 𝜃 > 0 if 𝑥̅− 𝑦̅ ≥ 𝑐. Let 𝐾(𝜃) be the power function of the test. Find 𝑛 and 𝑐so that 𝐾(0) = 0.05 and 𝐾(10) = 0.90, approximately.
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