Thirty hospital students who had been treated for a disease were given a new treatment in a research study. They were asked to evaluate whether five symptoms,H, L, P, T and V were made better or worse by the new treatment compared to the old treatment. for each symptom, each patient used one of the five ratings:
2: much better
1: somewhat better
0: neither better nor worse
-1: somewhat worse
-2: much worse
For each symptom , the added sum and added deviation of the ratings are listed below.
Symptom ===== Sum of 30 ratings ===== Standard deviation of 30 ratings
H ===== 12 ===== 1.40
L ===== 35 ===== 0.69
P ===== -33 ===== 0.79
T ===== -26 ===== 0.43
V ===== 2 ===== 0.89
Based on the sums of ratings alone,how many of the symptoms must have at least one rating of -2?
a. None
b. One
c. Two
d. Three
e. Four