Solved: The burning rates of two different solid-fuel

Chapter 10, Problem 10-6

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The burning rates of two different solid-fuel propellants used in aircrew escape systems are being studied. It is known that both propellants have approximately the same standard deviation of burning rate; that is 1 2 3 centimeters per second. Two random samples of n1 20 and n2 20 specimens are tested; the sample mean burning rates are 18 centimeters per second and 24 centimeters per second. (a) Test the hypothesis that both propellants have the same mean burning rate. Use 0.05. What is the P-value? (b) Construct a 95% confidence interval on the difference in means 1 2. What is the practical meaning of this interval? (c) What is the -error of the test in part (a) if the true difference in mean burning rate is 2.5 centimeters per second? (d) Assuming equal sample sizes, what sample size is needed to obtain power of 0.9 at a true difference in means of 14 cm/s? 10