Finding the Fourth Proportional to 1,399.86, 2,100.42 and 534.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.86 : 2,100.42 = 534.78 : x
2. Step 2: Convert to fraction form
   1,399.86/2,100.42 = 534.78/x
3. Step 3: Cross multiply
   1,399.86x = 2,100.42 × 534.78
4. Step 4: Simplify right side
   1,399.86x = 1,123,262.61
5. Step 5: Solve for x
   x = 1,123,262.61/1,399.86
6. Step 6: Final answer
   x = 802.41