A dry etch process is used to etch silicon dioxide (SiO2) off of silicon wafers. An engineer wishes to study the uniformity of the etching across the surface of the wafer. A total of 10 wafers are sampled after etching, and the etch rates (in A —¦ /min) are measured at two different sites, one near the center of the wafer, and one near the edge. The results are presented in the following table.

Can you conclude that the etch rates differ between the center and the edge?

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Wafer Cer Edge 586 568 587 550 543 552 562 577 558 571 582 569 587 543 540 548 563 572 559 566 3 10