21. Teaching Methods A new method of teaching reading is beingtested
on third grade students. A group of third grade students is taughtusing
the new curriculum. A control group of third grade students istaught
using the old curriculum. The reading test scores for the twogroups are
shown in the back-to-back stem-and-leaf plot.
Old Curriculum New Curriculum
9 3
9 9 4 3
9 8 8 4 3 3 2 1 5 2 4
7 6 4 2 2 1 0 0 6 0 1 1 4 7 7 7 7 7 8 9 9
7 0 1 1 2 3 3 4 9
8 2 4
Key: 9 0 4 0 3 = 49 for old curriculum and 43 for newcurriculum
At a = 0.10, is there enough evidence to support the claim that thenew
method of teaching reading produces higher reading test scores thanthe
old method does? Assume the population variances are equal.
