Finding the Fourth Proportional to 1,380.39, 1,900.56 and 1,170.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.39 : 1,900.56 = 1,170.10 : x
2. Step 2: Convert to fraction form
   1,380.39/1,900.56 = 1,170.10/x
3. Step 3: Cross multiply
   1,380.39x = 1,900.56 × 1,170.10
4. Step 4: Simplify right side
   1,380.39x = 2,223,845.26
5. Step 5: Solve for x
   x = 2,223,845.26/1,380.39
6. Step 6: Final answer
   x = 1,611.03