Table MTC0. Confidence interval for difference of two means (large n, equal n’s)

Computed using the large sample normal approximation with the z distribution. See nQuery Advisor® manual Appendix or the table guide cards for the computing formula. Figure MTC0 shows computations for one example. Additional values tested: confidence levels from 0.6 to 0.99 with interval width .2σ, σ to n and n of 16, 2000 to interval width. Checked against hand calculations and published examples.

Figure MTC0. In the first column, nQuery Advisor® 7.0 computed interval width, and in the second column, nQuery Advisor® 7.0 computed n.