Finding the Fourth Proportional to 1,385.80, 1,914.42 and 1,282.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.80 : 1,914.42 = 1,282.12 : x
2. Step 2: Convert to fraction form
   1,385.80/1,914.42 = 1,282.12/x
3. Step 3: Cross multiply
   1,385.80x = 1,914.42 × 1,282.12
4. Step 4: Simplify right side
   1,385.80x = 2,454,516.17
5. Step 5: Solve for x
   x = 2,454,516.17/1,385.80
6. Step 6: Final answer
   x = 1,771.19