Finding the Fourth Proportional to 1,406.76, 1,938.90 and 1,209.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,406.76 : 1,938.90 = 1,209.48 : x
2. Step 2: Convert to fraction form
   1,406.76/1,938.90 = 1,209.48/x
3. Step 3: Cross multiply
   1,406.76x = 1,938.90 × 1,209.48
4. Step 4: Simplify right side
   1,406.76x = 2,345,060.77
5. Step 5: Solve for x
   x = 2,345,060.77/1,406.76
6. Step 6: Final answer
   x = 1,666.99