Finding the Fourth Proportional to 1,005.48, 1,504.32 and 615.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.48 : 1,504.32 = 615.42 : x
2. Step 2: Convert to fraction form
   1,005.48/1,504.32 = 615.42/x
3. Step 3: Cross multiply
   1,005.48x = 1,504.32 × 615.42
4. Step 4: Simplify right side
   1,005.48x = 925,788.61
5. Step 5: Solve for x
   x = 925,788.61/1,005.48
6. Step 6: Final answer
   x = 920.74