Finding the Fourth Proportional to 1,438.88, 1,985.67 and 915.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,438.88 : 1,985.67 = 915.62 : x
2. Step 2: Convert to fraction form
   1,438.88/1,985.67 = 915.62/x
3. Step 3: Cross multiply
   1,438.88x = 1,985.67 × 915.62
4. Step 4: Simplify right side
   1,438.88x = 1,818,109.24
5. Step 5: Solve for x
   x = 1,818,109.24/1,438.88
6. Step 6: Final answer
   x = 1,263.56