# Question: Suppose that x1 N 1 12 and x2 N 2

Suppose that x1 ~ N(1, 12) and x2 ~ N(2, 22), and that x1 and x2 are independent. Develop a procedure for constructing a 100(1 − )% confidence interval on 1 − 2, assuming that 12 and 22 are unknown and cannot be assumed equal.

## Answer to relevant Questions

(a) Test the hypothesis that the mean hardness for the saltwater quenching process equals the mean hardness for the oil quenching process. Use a = 0.05 and assume equal variances. Test H0: 1 2 = 0 vs. H1: 1 ...A new purification unit is installed in a chemical process. Before its installation, a random sample yielded the following data about the percentage of impurity: x12 9.85,s12 6.79 and n1 10 . After installation, a ...Suppose that you are testing the following hypotheses where the variance is known: H0 : 100 H1 : 100 Find the P-value for the following values of the test statistic. (a) Z0 = −2.35 (b) Z0 = −1.99 (c) Z0 = ...Compare the mean compressive strength at each rodding level from Exercise 4.37 with a scaled t distribution. What conclusions would you draw from this plot? The brake horsepower developed by an automobile engine on a dynamometer is thought to be a function of the engine speed in revolutions per minute (rpm), the road octane number of the fuel, and the engine compression. An ...Post your question