Finding the Fourth Proportional to 12,428.58, 17,152.65 and 9,279.30

Step by Step Solution

1. Step 1: Write the proportion equation
   12,428.58 : 17,152.65 = 9,279.30 : x
2. Step 2: Convert to fraction form
   12,428.58/17,152.65 = 9,279.30/x
3. Step 3: Cross multiply
   12,428.58x = 17,152.65 × 9,279.30
4. Step 4: Simplify right side
   12,428.58x = 159,164,585.15
5. Step 5: Solve for x
   x = 159,164,585.15/12,428.58
6. Step 6: Final answer
   x = 12,806.34