The sign test is used with $n=9$ to test the null hypothesis that the new method and the old method produce equally high scores against the alternative hypothesis that the new method produces higher scores than the old. If we obtain eight plus signs in subtracting (new score - old score), then with $\alpha=0.05$, the null hypothesis should
A) be rejected since $6

Question

The sign test is used with $n=9$ to test the null hypothesis that the new method and the old method produce equally high scores against the alternative hypothesis that the new method produces higher scores than the old. If we obtain eight plus signs in subtracting (new score - old score), then with $\alpha=0.05$, the null hypothesis should
A) be rejected since $6<7$.
B) not be rejected since $6<7$.
C) be rejected since $7<8$.
D) not be rejected since $7<8$.

Quizplus · Accepted Answer

The sign test is a non-parametric test used to determine if there are more positive differences than would be expected by chance if the two methods were equally good. With $n=9$ and eight plus signs, we are looking at a one-tailed test (since we're testing if the new method is better). The critical value for $\alpha=0.05$ with $n=9$ in a one-tailed test is 7 (meaning we would expect 7 or fewer plus signs by chance if the null hypothesis were true). Since we have 8 plus signs, which is greater than 7, we reject the null hypothesis in favor of the alternative that the new method produces higher scores.

The Sign Test Is Used With n=9n=9n=9 To Test the Null Hypothesis That the New Method and Null

The Sign Test Is Used With $n=9$ To Test the Null Hypothesis That the New Method and Null