Finding the Fourth Proportional to 876.89, 1,209.89 and 503.98

Step by Step Solution

1. Step 1: Write the proportion equation
   876.89 : 1,209.89 = 503.98 : x
2. Step 2: Convert to fraction form
   876.89/1,209.89 = 503.98/x
3. Step 3: Cross multiply
   876.89x = 1,209.89 × 503.98
4. Step 4: Simplify right side
   876.89x = 609,758.60
5. Step 5: Solve for x
   x = 609,758.60/876.89
6. Step 6: Final answer
   x = 695.36