Question

A mixture of pulverized fuel ash and Portland cement to be used for grouting should have a compressive strength of more than 1300 KN/m2. The mixture will not be used unless experimental evidence indicates conclusively that the strength specification has been met. Suppose compressive strength for specimens of this mixture is normally distributed with σ-60. Let μ denote the true average compressive strength (a) What are the appropriate null and alternative hypotheses? Ho: μ 1300 (b) Let X denote the sample average compressive strength for n 12 randomly selected specimens. Consider the test procedure with test statistic X itself (not standardized). What is the probability distribution of the test statistic when Ho is true? The test statistic has an exponential distribution The test statistic has a normal distribution. The test statistic has a binomial distribution. The test statistic has a gamma distribution. If X = 1340, find the P-value. (Round your answer to four decimal places.) P-value0.9958 Should Ho be rejected using a significance level of 0.01? reject Ho do not reject Ho (c) What is the probability distribution of the test statistic when u1350? The test statistic has a binomial distribution. The test statistic has a normal distribution. The test statistic has a gamma distribution The test statistic has an exponential distribution State the mean and standard deviation of the test statistic. (Round your standard deviation to three decimal places.) mean standard deviation Ans KN/m2 KN/m2 Ans 1350 (a type 11 error)? (Round your answer to four For a test with α-0.01, what is the probability that the mixture will be judged unsatisfactory when in fact μ decimal places.) Ans You may need to use the appropriate table in the Appendix of Tables to answer this question

Answer 1

ms. 1340 ..)300 2.31 ナ//n_ Z 2.31 1 0.956 1.32