Finding the Fourth Proportional to 1,155.91, 1,734.59 and 669.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,155.91 : 1,734.59 = 669.91 : x
2. Step 2: Convert to fraction form
   1,155.91/1,734.59 = 669.91/x
3. Step 3: Cross multiply
   1,155.91x = 1,734.59 × 669.91
4. Step 4: Simplify right side
   1,155.91x = 1,162,019.19
5. Step 5: Solve for x
   x = 1,162,019.19/1,155.91
6. Step 6: Final answer
   x = 1,005.29