1. The problem is to analyze the data of hours of sleep for 45 patients after administration of a hypnotic drug, arranged in a 5x9 table. 2. We can calculate the mean (average) hours of sleep to understand the central tendency of the data. 3. The formula for the mean is $$\text{Mean} = \frac{\sum \text{all values}}{\text{number of values}}$$. 4. First, sum all the values in the table: Row 1: 12 + 5 + 8 + 3 + 7 + 8 + 4 + 10 + 7 = 64 Row 2: 5 + 4 + 4 + 10 + 13 + 1 + 1 + 8 + 11 = 57 Row 3: 1 + 13 + 8 + 3 + 2 + 3 + 7 + 8 + 5 = 50 Row 4: 10 + 17 + 1 + 3 + 5 + 4 + 7 + 17 + 4 = 68 Row 5: 8 + 5 + 3 + 7 + 4 + 12 + 10 + 7 + 4 = 60 5. Sum of all values = 64 + 57 + 50 + 68 + 60 = 299 6. Number of values = 45 (5 rows * 9 columns) 7. Calculate the mean: $$\text{Mean} = \frac{299}{45} \approx 6.644$$ 8. Therefore, the average hours of sleep for the patients is approximately 6.64 hours.