Finding the Fourth Proportional to 28,627, 42,948.20 and 11,978.24

Step by Step Solution

1. Step 1: Write the proportion equation
   28,627 : 42,948.20 = 11,978.24 : x
2. Step 2: Convert to fraction form
   28,627/42,948.20 = 11,978.24/x
3. Step 3: Cross multiply
   28,627x = 42,948.20 × 11,978.24
4. Step 4: Simplify right side
   28,627x = 514,443,847.17
5. Step 5: Solve for x
   x = 514,443,847.17/28,627
6. Step 6: Final answer
   x = 17,970.58