Finding the Fourth Proportional to 1,387.23, 1,915.20 and 1,032.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.23 : 1,915.20 = 1,032.72 : x
2. Step 2: Convert to fraction form
   1,387.23/1,915.20 = 1,032.72/x
3. Step 3: Cross multiply
   1,387.23x = 1,915.20 × 1,032.72
4. Step 4: Simplify right side
   1,387.23x = 1,977,865.34
5. Step 5: Solve for x
   x = 1,977,865.34/1,387.23
6. Step 6: Final answer
   x = 1,425.77