Finding the Fourth Proportional to 431.83, 647.78 and 123.67

Step by Step Solution

1. Step 1: Write the proportion equation
   431.83 : 647.78 = 123.67 : x
2. Step 2: Convert to fraction form
   431.83/647.78 = 123.67/x
3. Step 3: Cross multiply
   431.83x = 647.78 × 123.67
4. Step 4: Simplify right side
   431.83x = 80,111.61
5. Step 5: Solve for x
   x = 80,111.61/431.83
6. Step 6: Final answer
   x = 185.52