Finding the Fourth Proportional to 1,389.89, 1,915.72 and 1,053.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.89 : 1,915.72 = 1,053.69 : x
2. Step 2: Convert to fraction form
   1,389.89/1,915.72 = 1,053.69/x
3. Step 3: Cross multiply
   1,389.89x = 1,915.72 × 1,053.69
4. Step 4: Simplify right side
   1,389.89x = 2,018,572.48
5. Step 5: Solve for x
   x = 2,018,572.48/1,389.89
6. Step 6: Final answer
   x = 1,452.32