Finding the Fourth Proportional to 1,089.30, 1,503.46 and 690.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,089.30 : 1,503.46 = 690.70 : x
2. Step 2: Convert to fraction form
   1,089.30/1,503.46 = 690.70/x
3. Step 3: Cross multiply
   1,089.30x = 1,503.46 × 690.70
4. Step 4: Simplify right side
   1,089.30x = 1,038,439.82
5. Step 5: Solve for x
   x = 1,038,439.82/1,089.30
6. Step 6: Final answer
   x = 953.31