Finding the Fourth Proportional to 10,858.59, 14,978.12 and 7,877.79

Step by Step Solution

1. Step 1: Write the proportion equation
   10,858.59 : 14,978.12 = 7,877.79 : x
2. Step 2: Convert to fraction form
   10,858.59/14,978.12 = 7,877.79/x
3. Step 3: Cross multiply
   10,858.59x = 14,978.12 × 7,877.79
4. Step 4: Simplify right side
   10,858.59x = 117,994,444.57
5. Step 5: Solve for x
   x = 117,994,444.57/10,858.59
6. Step 6: Final answer
   x = 10,866.46