Finding the Fourth Proportional to 9,912.34, 13,678.95 and 5,720.50

Step by Step Solution

1. Step 1: Write the proportion equation
   9,912.34 : 13,678.95 = 5,720.50 : x
2. Step 2: Convert to fraction form
   9,912.34/13,678.95 = 5,720.50/x
3. Step 3: Cross multiply
   9,912.34x = 13,678.95 × 5,720.50
4. Step 4: Simplify right side
   9,912.34x = 78,250,433.48
5. Step 5: Solve for x
   x = 78,250,433.48/9,912.34
6. Step 6: Final answer
   x = 7,894.24