Six second grade students tried tossing a ball into a basket ten times each. Their teacher tl suggested a different way of tossing the ball, and the six students tried again. The numbe successful tosses, before and after the teacher's suggestion, are shown below.
$\begin{array}{c|cccccc}
\text { Student } & \text { A } & \text { B } & \text { C } & \text { D } & \text { E } & \text { F } \
\hline \text { Before the suggestion (out of 10) } & 5 & 3 & 5 & 4 & 5 & 3 \
\text { After the suggestion (out of 10) } & 2 & 3 & 2 & 6 & 2 & 3
\end{array}$

Find the positive rank sum. [Recall, differences of zero are not ranked.]
A) +3
B) +9
C) +15
D) +1

Question

Six second grade students tried tossing a ball into a basket ten times each. Their teacher tl suggested a different way of tossing the ball, and the six students tried again. The numbe successful tosses, before and after the teacher's suggestion, are shown below.
$\begin{array}{c|cccccc}
\text { Student } & \text { A } & \text { B } & \text { C } & \text { D } & \text { E } & \text { F } \
\hline \text { Before the suggestion (out of 10) } & 5 & 3 & 5 & 4 & 5 & 3 \
\text { After the suggestion (out of 10) } & 2 & 3 & 2 & 6 & 2 & 3
\end{array}$

Find the positive rank sum. [Recall, differences of zero are not ranked.]
A) +3
B) +9
C) +15
D) +1

Quizplus · Accepted Answer

The positive rank sum is calculated by ranking the differences in scores (after - before) and summing the ranks for the positive differences. Here, only Student D improved (6 - 4 = +2), so it gets the highest rank, which is 1. Thus, the positive rank sum is +1. However, the correct calculation involves summing all positive ranks, which in this case, due to the misunderstanding in explanation, should still focus on the fact that only improvements (positive changes) are considered. Given the data, it seems there was a misinterpretation in the initial explanation. The correct approach would involve identifying all improvements and summing their ranks, but based on the provided data, only one student showed improvement, leading to a confusion in the explanation provided.

Six Second Grade Students Tried Tossing a Ball into a Basket