Ten healthy adult subjects were asked to walk on a treadmill while connected to monitors. One of two kinds of disturbances was applied during the walk, and the number of steps until adaptation was recorded. Each subject experienced both kinds of disturbance, in random order. Here are the summary data for these 10 subjects:
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$$\begin{array} { | l | l | l | l | l | }
\hline & \mathrm { N } & \text { Mean } & \text { StDev } & \text { SE Mean } \
\hline \text { Disturbance A } & 10 & 7.320 & 2.10016 & 0.66413 \
\hline \text { Disturbance B } & 10 & 5.170 & 1.86073 & 0.58842 \
\hline \text { Difference A-B } & 10 & 2.150 & 2.68711 & 0.84974 \
\hline
\end{array}$$ What are the null and alternative hypotheses to test whether there is significant evidence of a different mean adaptation time (in steps) for the two disturbances?

Question

Ten healthy adult subjects were asked to walk on a treadmill while connected to monitors. One of two kinds of disturbances was applied during the walk, and the number of steps until adaptation was recorded. Each subject experienced both kinds of disturbance, in random order. Here are the summary data for these 10 subjects:
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$$\begin{array} { | l | l | l | l | l | } 
\hline & \mathrm { N } & \text { Mean } & \text { StDev } & \text { SE Mean } \
\hline \text { Disturbance A } & 10 & 7.320 & 2.10016 & 0.66413 \
\hline \text { Disturbance B } & 10 & 5.170 & 1.86073 & 0.58842 \
\hline \text { Difference A-B } & 10 & 2.150 & 2.68711 & 0.84974 \
\hline
\end{array}$$ What are the null and alternative hypotheses to test whether there is significant evidence of a different mean adaptation time (in steps) for the two disturbances?

Quizplus · Accepted Answer

The correct null hypothesis (H0) is that the mean difference between Disturbance A and Disturbance B is 0, indicating no difference in adaptation times between the two disturbances. The alternative hypothesis (Ha) is that the mean difference is not equal to 0, suggesting a significant difference in adaptation times. This is represented in choice B, which correctly sets up the hypotheses for testing the difference in means.

Ten Healthy Adult Subjects Were Asked to Walk on a Treadmill