Writers
Eight Professional Food Writers Have Been Asked to Rate

Writers
Eight professional food writers have been asked to rate the taste characteristics of a meat dish prepared first by flame grilling and then by charcoal grilling. After each of the dishes is prepared it is rated on a scale from 1 to 5 with 1 being best and 5 being worst. The results of the rating were:
$$\begin{array} { | c | c | c | c c | } \hline \text { Writer } & \text { Flame } & \text { Charcoal } & d _ { i } & \left| d _ { i } \right| \\\hline \text { A } & 5 & 1 & 4 & 4 \\\text { B } & 4 & 2 & 2 & 2 \\\text { C } & 1 & 2 & - 1 & 1 \\\text { D } & 4 & 3 & 1 & 1 \\\text { E } & 3 & 1 & 2 & 2 \\\text { F } & 4 & 4 & 0 & 0 \\\text { G } & 4 & 5 & - 1 & 1 \\\text { H } & 2 & 3 & - 1 & 1 \\\hline\end{array}$$
-In testing the hypotheses H₀: m_d = 0,H₁: m_d ≠ 0,data are drawn from a matched pairs experiment,and the following statistics are calculated: n = number of nonzero differences = 40; R+ = 238; R- = 582.Assume that the 5% level of significance is used.Calculate the z-approximation test statistic.