Finding the Fourth Proportional to 1,389.88, 1,931.51 and 1,372.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.88 : 1,931.51 = 1,372.46 : x
2. Step 2: Convert to fraction form
   1,389.88/1,931.51 = 1,372.46/x
3. Step 3: Cross multiply
   1,389.88x = 1,931.51 × 1,372.46
4. Step 4: Simplify right side
   1,389.88x = 2,650,910.91
5. Step 5: Solve for x
   x = 2,650,910.91/1,389.88
6. Step 6: Final answer
   x = 1,907.29