Finding the Fourth Proportional to 1,090.91, 1,505.30 and 648.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,090.91 : 1,505.30 = 648.72 : x
2. Step 2: Convert to fraction form
   1,090.91/1,505.30 = 648.72/x
3. Step 3: Cross multiply
   1,090.91x = 1,505.30 × 648.72
4. Step 4: Simplify right side
   1,090.91x = 976,514.97
5. Step 5: Solve for x
   x = 976,514.97/1,090.91
6. Step 6: Final answer
   x = 895.14