Finding the Fourth Proportional to 9,880.79, 14,820.57 and 5,199.39

Step by Step Solution

1. Step 1: Write the proportion equation
   9,880.79 : 14,820.57 = 5,199.39 : x
2. Step 2: Convert to fraction form
   9,880.79/14,820.57 = 5,199.39/x
3. Step 3: Cross multiply
   9,880.79x = 14,820.57 × 5,199.39
4. Step 4: Simplify right side
   9,880.79x = 77,057,923.45
5. Step 5: Solve for x
   x = 77,057,923.45/9,880.79
6. Step 6: Final answer
   x = 7,798.77