The Accompanying Data Resulted from an Experiment to Compare the Effects

Essay

The accompanying data resulted from an experiment to compare the effects of vitamin C in orange juice and in synthetic ascorbic acid on the length of odontoblasts in guinea pigs over a 6-week period. Use the Wilcoxon rank-sum test at level .01 to decide whether true length differs for the two types of vitamin C intake. Compute also an approximate P-value. $$\begin{array} { l c c c c c c c c c c } \hline \text { Orange juice } & 8.5 & 9.7 & 9.9 & 10.0 & 10.3 & 14.8 & 15.5 & 16.4 & 17.9 & 21.8 \\\hline \text { Ascorbic acid } & 4.5 & 5.5 & 6.1 & 6.7 & 7.3 & 7.6 & 10.4 & 11.5 & 11.6 & 11.8 \\\hline\end{array}$$