Finding the Fourth Proportional to 1,385.69, 2,079.52 and 769.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.69 : 2,079.52 = 769.89 : x
2. Step 2: Convert to fraction form
   1,385.69/2,079.52 = 769.89/x
3. Step 3: Cross multiply
   1,385.69x = 2,079.52 × 769.89
4. Step 4: Simplify right side
   1,385.69x = 1,601,001.65
5. Step 5: Solve for x
   x = 1,601,001.65/1,385.69
6. Step 6: Final answer
   x = 1,155.38