Finding the Fourth Proportional to 328,928.56, 491,012.72 and 289,071.52

Step by Step Solution

1. Step 1: Write the proportion equation
   328,928.56 : 491,012.72 = 289,071.52 : x
2. Step 2: Convert to fraction form
   328,928.56/491,012.72 = 289,071.52/x
3. Step 3: Cross multiply
   328,928.56x = 491,012.72 × 289,071.52
4. Step 4: Simplify right side
   328,928.56x = 141,937,793,309.73
5. Step 5: Solve for x
   x = 141,937,793,309.73/328,928.56
6. Step 6: Final answer
   x = 431,515.56