Finding the Fourth Proportional to 928.53, 1,280.61 and 818.10

Step by Step Solution

1. Step 1: Write the proportion equation
   928.53 : 1,280.61 = 818.10 : x
2. Step 2: Convert to fraction form
   928.53/1,280.61 = 818.10/x
3. Step 3: Cross multiply
   928.53x = 1,280.61 × 818.10
4. Step 4: Simplify right side
   928.53x = 1,047,667.04
5. Step 5: Solve for x
   x = 1,047,667.04/928.53
6. Step 6: Final answer
   x = 1,128.31