Finding the Fourth Proportional to 1,091.89, 1,506.09 and 699.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,091.89 : 1,506.09 = 699.40 : x
2. Step 2: Convert to fraction form
   1,091.89/1,506.09 = 699.40/x
3. Step 3: Cross multiply
   1,091.89x = 1,506.09 × 699.40
4. Step 4: Simplify right side
   1,091.89x = 1,053,359.35
5. Step 5: Solve for x
   x = 1,053,359.35/1,091.89
6. Step 6: Final answer
   x = 964.71