Finding the Fourth Proportional to 28,607.50, 42,917.74 and 10,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   28,607.50 : 42,917.74 = 10,139.50 : x
2. Step 2: Convert to fraction form
   28,607.50/42,917.74 = 10,139.50/x
3. Step 3: Cross multiply
   28,607.50x = 42,917.74 × 10,139.50
4. Step 4: Simplify right side
   28,607.50x = 435,164,424.73
5. Step 5: Solve for x
   x = 435,164,424.73/28,607.50
6. Step 6: Final answer
   x = 15,211.55