Finding the Fourth Proportional to 1,431.30, 1,973.34 and 1,218.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,431.30 : 1,973.34 = 1,218.42 : x
2. Step 2: Convert to fraction form
   1,431.30/1,973.34 = 1,218.42/x
3. Step 3: Cross multiply
   1,431.30x = 1,973.34 × 1,218.42
4. Step 4: Simplify right side
   1,431.30x = 2,404,356.92
5. Step 5: Solve for x
   x = 2,404,356.92/1,431.30
6. Step 6: Final answer
   x = 1,679.84