Finding the Fourth Proportional to 1,090.89, 1,505.31 and 648.73

Step by Step Solution

1. Step 1: Write the proportion equation
   1,090.89 : 1,505.31 = 648.73 : x
2. Step 2: Convert to fraction form
   1,090.89/1,505.31 = 648.73/x
3. Step 3: Cross multiply
   1,090.89x = 1,505.31 × 648.73
4. Step 4: Simplify right side
   1,090.89x = 976,539.76
5. Step 5: Solve for x
   x = 976,539.76/1,090.89
6. Step 6: Final answer
   x = 895.18