Finding the Fourth Proportional to 1,538.76, 2,123.48 and 840.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.76 : 2,123.48 = 840.12 : x
2. Step 2: Convert to fraction form
   1,538.76/2,123.48 = 840.12/x
3. Step 3: Cross multiply
   1,538.76x = 2,123.48 × 840.12
4. Step 4: Simplify right side
   1,538.76x = 1,783,978.02
5. Step 5: Solve for x
   x = 1,783,978.02/1,538.76
6. Step 6: Final answer
   x = 1,159.36