Finding the Fourth Proportional to 13,307.85, 19,961.67 and 3,947.89

Step by Step Solution

1. Step 1: Write the proportion equation
   13,307.85 : 19,961.67 = 3,947.89 : x
2. Step 2: Convert to fraction form
   13,307.85/19,961.67 = 3,947.89/x
3. Step 3: Cross multiply
   13,307.85x = 19,961.67 × 3,947.89
4. Step 4: Simplify right side
   13,307.85x = 78,806,477.38
5. Step 5: Solve for x
   x = 78,806,477.38/13,307.85
6. Step 6: Final answer
   x = 5,921.80