Finding the Fourth Proportional to 28,412.76, 42,602.72 and 12,617.76

Step by Step Solution

1. Step 1: Write the proportion equation
   28,412.76 : 42,602.72 = 12,617.76 : x
2. Step 2: Convert to fraction form
   28,412.76/42,602.72 = 12,617.76/x
3. Step 3: Cross multiply
   28,412.76x = 42,602.72 × 12,617.76
4. Step 4: Simplify right side
   28,412.76x = 537,550,896.31
5. Step 5: Solve for x
   x = 537,550,896.31/28,412.76
6. Step 6: Final answer
   x = 18,919.35