Finding the Fourth Proportional to 2,312.10, 3,189.45 and 1,380.42

Step by Step Solution

1. Step 1: Write the proportion equation
   2,312.10 : 3,189.45 = 1,380.42 : x
2. Step 2: Convert to fraction form
   2,312.10/3,189.45 = 1,380.42/x
3. Step 3: Cross multiply
   2,312.10x = 3,189.45 × 1,380.42
4. Step 4: Simplify right side
   2,312.10x = 4,402,780.57
5. Step 5: Solve for x
   x = 4,402,780.57/2,312.10
6. Step 6: Final answer
   x = 1,904.23