Finding the Fourth Proportional to 1,109.79, 1,531.30 and 612.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.79 : 1,531.30 = 612.42 : x
2. Step 2: Convert to fraction form
   1,109.79/1,531.30 = 612.42/x
3. Step 3: Cross multiply
   1,109.79x = 1,531.30 × 612.42
4. Step 4: Simplify right side
   1,109.79x = 937,793.27
5. Step 5: Solve for x
   x = 937,793.27/1,109.79
6. Step 6: Final answer
   x = 845.02