Finding the Fourth Proportional to 1,375.78, 1,897.88 and 815.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,375.78 : 1,897.88 = 815.98 : x
2. Step 2: Convert to fraction form
   1,375.78/1,897.88 = 815.98/x
3. Step 3: Cross multiply
   1,375.78x = 1,897.88 × 815.98
4. Step 4: Simplify right side
   1,375.78x = 1,548,623.30
5. Step 5: Solve for x
   x = 1,548,623.30/1,375.78
6. Step 6: Final answer
   x = 1,125.63