Finding the Fourth Proportional to 1,002.42, 1,505.76 and 612.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,002.42 : 1,505.76 = 612.60 : x
2. Step 2: Convert to fraction form
   1,002.42/1,505.76 = 612.60/x
3. Step 3: Cross multiply
   1,002.42x = 1,505.76 × 612.60
4. Step 4: Simplify right side
   1,002.42x = 922,428.58
5. Step 5: Solve for x
   x = 922,428.58/1,002.42
6. Step 6: Final answer
   x = 920.20