Reconsider the situation of Exercise 73, in which x = retained austenite content using a...

Reconsider the situation of Exercise 73, in which x = retained austenite content using a garnet abrasive and y = abrasive wear loss were related via the simple linear regression model . Suppose that for a second type of abrasive, these variables are also related via the simple linear regression model and that for both types of abrasive. If the data set consists of n1 observations on the first abrasive and n₂ on the second and if SSE₁ and SSE₂ denote the two error sums of squares, then a pooled estimate of σ² is denote or the data on the first and second abrasives, respectively. A test of (equal slopes) is based on the statistic

When H0 is true, T has a t distribution with df. Suppose the 15 observations using the alternative abrasive Give , and Using this along with the data of Exercise 73, carry out a test at level .05 to see whether expected change in wear loss associated with a 1% increase in austenite content is identical for the two types of abrasive.