Finding the Fourth Proportional to 10,779.84, 16,170.72 and 7,830.72

Step by Step Solution

1. Step 1: Write the proportion equation
   10,779.84 : 16,170.72 = 7,830.72 : x
2. Step 2: Convert to fraction form
   10,779.84/16,170.72 = 7,830.72/x
3. Step 3: Cross multiply
   10,779.84x = 16,170.72 × 7,830.72
4. Step 4: Simplify right side
   10,779.84x = 126,628,380.52
5. Step 5: Solve for x
   x = 126,628,380.52/10,779.84
6. Step 6: Final answer
   x = 11,746.78