e, the cell references again are automatically updated formula in cell H12 is "=(D5-J5)^ 2/J5"). x test statistic is computed by summing the (O – ues in the twelve cells. The test statistic is placed in cell is computed using “=SUM(F9:H12)". The p-value is ed with the CHIDIST function using "= CHIDIST ;where 6 reflects the degrees of freedom (df = (r – 1) ) = 3(2) = 6). The test statistic and p-value are shown e 7-28. 7.9 PRACTICE PROBLEMS 1. Data are collected in a clinical trial evaluating a new compound designed to improve wound healing in trauma patients. The new compound is compared against a placebo. After treatment for 5 days with the new compound or placebo, the extent of wound heal- ing is measured and the data are shown in Table 7-6. Is there a difference in the extent of wound healing by %3D %3D nis test, the test statistic is x = 60.44 and the p-value cally zero (3.66 X 10-11). We reject H, because p = = 0.05. We have statistically significant evidence at a to show that H is false, or that living arrangement rcise are not independent (i.e., they are dependent or TABLE 7-6 Data for Practice Problems 1 and 2 Percent Wound Healing Treatment 0-25% 26-50% 51-75% 76-100% New compound (n = 125) 15 37 32 41 %3D Placebo (n= 125) 36 45 34 10 へ Ca ) EN df (SECURED)-Adobe Acrobat Pro DC 84108217 W... x 112 /231 Ф 149% Practice Problems 107 treatment? (Hint: Are treatment and the percent wound healing independent?) Run the appropriate test at a 5% level of significance. 2. Use the data in Problem 1 and pool the data across the signed medication and their systolic blood pressure (SBP) is recorded after 6 months on the assigned medication. The data are shown in Table 7–9. Is there a difference in mean SBP between treatments? Run treatments into one sample of size n = 250. Use the pooled data to test whether the distribution of the percent wound healing is approximately normal. Specifically, use the following distribution: 30%, 40%, 20%, and 10%. Run the appropriate test at a = 0.05. 3. The data in Table 7-7 are collected in an experiment designed to investigate the impact of different posi- tions of the mother during ultrasound on fetal heart rate. Fetal heart rate is measured by ultrasound in the appropriate test at a = 0.05. TABLE 7-7 Data for Practice Problem 3 beats minute. The study includes 20 women who are each assigned to one position and have the fetal heart rate measured in that position. Each woman is between 28 weeks and 32 weeks gestation. Is there a significant difference in mean fetal heart rates by po- sition? Run the test at a 5% level of significance. per Back Side Sitting Standing 140 141 144 147 144 143 145 145 146 145 147 146 141 144 148 149 139 136 144 145 Pa w] へま Ca 4) ENG 9/