Finding the Fourth Proportional to 1,047.94, 1,570.84 and 431.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,047.94 : 1,570.84 = 431.98 : x
2. Step 2: Convert to fraction form
   1,047.94/1,570.84 = 431.98/x
3. Step 3: Cross multiply
   1,047.94x = 1,570.84 × 431.98
4. Step 4: Simplify right side
   1,047.94x = 678,577.72
5. Step 5: Solve for x
   x = 678,577.72/1,047.94
6. Step 6: Final answer
   x = 647.54