Finding the Fourth Proportional to 1,380.51, 1,903.89 and 1,098.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.51 : 1,903.89 = 1,098.63 : x
2. Step 2: Convert to fraction form
   1,380.51/1,903.89 = 1,098.63/x
3. Step 3: Cross multiply
   1,380.51x = 1,903.89 × 1,098.63
4. Step 4: Simplify right side
   1,380.51x = 2,091,670.67
5. Step 5: Solve for x
   x = 2,091,670.67/1,380.51
6. Step 6: Final answer
   x = 1,515.14