Finding the Fourth Proportional to 1,427.42, 2,139.89 and 1,209.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,427.42 : 2,139.89 = 1,209.47 : x
2. Step 2: Convert to fraction form
   1,427.42/2,139.89 = 1,209.47/x
3. Step 3: Cross multiply
   1,427.42x = 2,139.89 × 1,209.47
4. Step 4: Simplify right side
   1,427.42x = 2,588,116.01
5. Step 5: Solve for x
   x = 2,588,116.01/1,427.42
6. Step 6: Final answer
   x = 1,813.14