III . = 1.75, s = 2.49, , df = 8 – 1 = 7.0.025 < P < 0.05 (from Table A).Using the T-Test function in the STAT TESTS menu of the TI-83/84, the P -value = 0.044.
IV . The P -value is small. This provides us with evidence that, over the past two years, there
have been more absences on Mondays than on Wednesdays.Inference for the Difference Between Two Population Means
The two-sample case for the difference in the means of two independent samples is more complicated
than the one-sample case. The hypothesis testing logic is identical, however, so the differences are in the
mechanics needed to do the problems, not in the process. For hypotheses about the differences between
two means, the procedures are summarized in the following table.
• The second rows for conditions and test statistic give the typical t -procedure approach. The