Finding the Fourth Proportional to 1,387.04, 1,914.72 and 920.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.04 : 1,914.72 = 920.48 : x
2. Step 2: Convert to fraction form
   1,387.04/1,914.72 = 920.48/x
3. Step 3: Cross multiply
   1,387.04x = 1,914.72 × 920.48
4. Step 4: Simplify right side
   1,387.04x = 1,762,461.47
5. Step 5: Solve for x
   x = 1,762,461.47/1,387.04
6. Step 6: Final answer
   x = 1,270.66