No. The interval refers to the mean math score, not to individual scores, which will be much more variable (indeed, if more than 95% of
students score below 470, they are not doing very well).
There almost certainly was some difference between the sexes and between blacks and whites; the observed difference between men and woman
was so large that it is unlikely to be due to chance. For black and white students, however, the difference was small enough that it could
be attributed to random variation.
Since
0.215 < 0.674, P > 0.25. (In fact,
P = P(Z > 0.215) = 0.4149). This assumes that the test gave some (weak) evidence in favour
of the alternative, e.g., we had
vs.
.
If the alternative had been
,
then
P = P(Z < 0.215), which is even bigger - that is, it gives even less reason to reject H0.
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