Finding the Fourth Proportional to 769.10, 1,061.91 and 720.50

Step by Step Solution

1. Step 1: Write the proportion equation
   769.10 : 1,061.91 = 720.50 : x
2. Step 2: Convert to fraction form
   769.10/1,061.91 = 720.50/x
3. Step 3: Cross multiply
   769.10x = 1,061.91 × 720.50
4. Step 4: Simplify right side
   769.10x = 765,100.85
5. Step 5: Solve for x
   x = 765,100.85/769.10
6. Step 6: Final answer
   x = 994.81