Finding the Fourth Proportional to 1,380.42, 2,066.34 and 1,031.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.42 : 2,066.34 = 1,031.70 : x
2. Step 2: Convert to fraction form
   1,380.42/2,066.34 = 1,031.70/x
3. Step 3: Cross multiply
   1,380.42x = 2,066.34 × 1,031.70
4. Step 4: Simplify right side
   1,380.42x = 2,131,842.98
5. Step 5: Solve for x
   x = 2,131,842.98/1,380.42
6. Step 6: Final answer
   x = 1,544.34