Finding the Fourth Proportional to 1,091.72, 1,506.60 and 649.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,091.72 : 1,506.60 = 649.70 : x
2. Step 2: Convert to fraction form
   1,091.72/1,506.60 = 649.70/x
3. Step 3: Cross multiply
   1,091.72x = 1,506.60 × 649.70
4. Step 4: Simplify right side
   1,091.72x = 978,838.02
5. Step 5: Solve for x
   x = 978,838.02/1,091.72
6. Step 6: Final answer
   x = 896.60