Finding the Fourth Proportional to 12,798.12, 19,153.80 and 7,870.86

Step by Step Solution

1. Step 1: Write the proportion equation
   12,798.12 : 19,153.80 = 7,870.86 : x
2. Step 2: Convert to fraction form
   12,798.12/19,153.80 = 7,870.86/x
3. Step 3: Cross multiply
   12,798.12x = 19,153.80 × 7,870.86
4. Step 4: Simplify right side
   12,798.12x = 150,756,878.27
5. Step 5: Solve for x
   x = 150,756,878.27/12,798.12
6. Step 6: Final answer
   x = 11,779.61