A production engineer claims that there is no difference in the mean nut diameter manufactured by two different methods. The first method produces nuts with the following diameters (in centimeters).
3.330 3.337 3.329 3.364 3.325 3.343 3.333 3.347 3.332 3.358
3.353 3.335 3.341 3.331 3.327 3.325 3.337 3.336 3.323 3.347
3.329 3.345 3.329 3.338 3.353 3.339 3.338 3.338 3.350 3.320
3.364 3.340 3.348 3.339 3.336 3.321 3.306 3.352 3.320 3.336
The second method produces nuts with theses diameters (in centimeters).
3.513 3.490 3.498 3.504 3.483 3.512 3.494 3.514 3.495 3.489
3.493 3.499 3.497 3.495 3.496 3.485 3.506 3.577 3.484 3.498
3.522 3.505 3.501 3.691 3.500 3.499 3.475 3.486 3.501 3.496
3.504 3.513 3.511 3.501 3.487 3.538 3.515 3.505 3.496 3.505
Use an alpha level of .01 and test the hypothesis that the two methods are producing the same mean.
a. Null Hypothesis;
b. Alternate Hypothesis:
c. Test statistic: