Finding the Fourth Proportional to 1,431.67, 1,975.79 and 872.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,431.67 : 1,975.79 = 872.05 : x
2. Step 2: Convert to fraction form
   1,431.67/1,975.79 = 872.05/x
3. Step 3: Cross multiply
   1,431.67x = 1,975.79 × 872.05
4. Step 4: Simplify right side
   1,431.67x = 1,722,987.67
5. Step 5: Solve for x
   x = 1,722,987.67/1,431.67
6. Step 6: Final answer
   x = 1,203.48