An experiment was conducted to compare a teacher-developed curriculum, "Biology: A Community Context" (BACC) that was standards-based, activity-oriented, and inquiry-centered to the traditional presentation using lecture, vocabulary, and memorized facts. The perhaps not-so startling results when students were tested on biology concepts, published in The American Biology Teacher, are shown in the following table.

a. Find a 95% confidence interval for the mean score for the posttest for all BACC classes.
b. Find a 95% confidence interval for the mean score for the posttest for all traditional classes.
c. Find a 95% confidence interval for the difference in mean scores for the posttest BACC classes and the posttest traditional classes.
d. Does the confidence interval in c provide evidence that there is a real difference in the posttest BACC and traditional class scores? Explain.

Transcribed Image Text:

Sample Standard Mean Size Deviation Pretest: All BACC Classes 13.38 372 14.06 368 Posttest: All BACC Classes 18.5 365 Posttest All Traditional 298 5.59 5.45 8.03 6.96 Pretest: All Traditional aditonal 165 298