Finding the Fourth Proportional to 1,109.68, 1,531.36 and 612.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.68 : 1,531.36 = 612.31 : x
2. Step 2: Convert to fraction form
   1,109.68/1,531.36 = 612.31/x
3. Step 3: Cross multiply
   1,109.68x = 1,531.36 × 612.31
4. Step 4: Simplify right side
   1,109.68x = 937,667.04
5. Step 5: Solve for x
   x = 937,667.04/1,109.68
6. Step 6: Final answer
   x = 844.99