Finding the Fourth Proportional to 13,776.31, 19,011.71 and 7,807.78

Step by Step Solution

1. Step 1: Write the proportion equation
   13,776.31 : 19,011.71 = 7,807.78 : x
2. Step 2: Convert to fraction form
   13,776.31/19,011.71 = 7,807.78/x
3. Step 3: Cross multiply
   13,776.31x = 19,011.71 × 7,807.78
4. Step 4: Simplify right side
   13,776.31x = 148,439,249.10
5. Step 5: Solve for x
   x = 148,439,249.10/13,776.31
6. Step 6: Final answer
   x = 10,774.96