A nutritionist is interested in determining the decrease in cholesterol level which a person can achieve by following a particular diet which is low in fat and high in fiber. Nine subjects are randomly selected to try the diet for six months, and their cholesterol levels are measured both before and after the diet. Use the sign test to analyze the results. The results of the study are as follows. Cholesterol Levels Subject 1 2 3 4 5 6 7 8 9 Before Diet 159 170 194 161 172 163 156 178 173 After Diet 164 168 194 157 172 161 152 173 173 Step 1 of 2 : Find the value of the test statistic. Round your answer to two decimal places, if necessary