Finding the Fourth Proportional to 8,985.90, 13,478.94 and 3,142.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,985.90 : 13,478.94 = 3,142.50 : x
2. Step 2: Convert to fraction form
   8,985.90/13,478.94 = 3,142.50/x
3. Step 3: Cross multiply
   8,985.90x = 13,478.94 × 3,142.50
4. Step 4: Simplify right side
   8,985.90x = 42,357,568.95
5. Step 5: Solve for x
   x = 42,357,568.95/8,985.90
6. Step 6: Final answer
   x = 4,713.78