Finding the Fourth Proportional to 1,431.60, 1,975.63 and 872.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,431.60 : 1,975.63 = 872.09 : x
2. Step 2: Convert to fraction form
   1,431.60/1,975.63 = 872.09/x
3. Step 3: Cross multiply
   1,431.60x = 1,975.63 × 872.09
4. Step 4: Simplify right side
   1,431.60x = 1,722,927.17
5. Step 5: Solve for x
   x = 1,722,927.17/1,431.60
6. Step 6: Final answer
   x = 1,203.50