Chance (Fall 2002) described a lawsuit where Intel Corp. was charged with infringing on a patent for an invention used in the automatic manufacture of computer chips. In response, Intel accused the inventor of adding material to his patent notebook after the patent was witnessed and granted. The case rested on whether a patent witness' signature was written on top of key text in the notebook or under the key text. Intel hired a physicist who used an X-ray beam to measure the relative concentration of certain elements (e.g., nickel, zinc, potassium) at several spots on the notebook page. The zinc measurements for three notebook locations-on a text line, on a witness line, and on the intersection of the witness and text lines -are provided in the table.

a. Use a test or a confidence interval (at a = .05) to compare the mean zinc measurement for the text line with the mean for the intersection.
b. Use a test or a confidence interval (at a = .05) to compare the mean zinc measurement for the witness line with the mean for the intersection.
c. From the results, parts a and b, what can you infer about the mean zinc measurements at the three notebook locations?
d. What assumptions are required for the inferences to be valid? Are they reasonably satisfied?

335 374 440 Text Line Witness Line 210 262 188 329 439 397 Intersection 33 353 285 295 319