A company that produces office chairs uses two machines, machine A and machine B, to test the weights of its chairs in order to ensure each chair is constructed properly. The manager of the company...

A company that produces office chairs uses two machines, machine A and machine B, to test the weights of its chairs in order to ensure each chair is constructed properly. The manager of the company randomly selects 8 chairs to be tested by machine A and 9 chairs to be tested by machine B. The table summarizes his data, including the standard error estimate (SE) for the difference in the two means and the approximate number of degrees of freedom (df).

The manager wishes to construct a 95%t‑confidence interval comparing the sample means of the weights of chairs processed by machine A and machine B. The manager is not willing to assume that the population variances are equal.

Determine the margin of error (?m) for the manager's 95%t‑confidence interval, rounded to four decimal places. You can use software or a ?t‑table to determine the critical value.