Finding the Fourth Proportional to 1,117.89, 1,542.71 and 620.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,117.89 : 1,542.71 = 620.53 : x
2. Step 2: Convert to fraction form
   1,117.89/1,542.71 = 620.53/x
3. Step 3: Cross multiply
   1,117.89x = 1,542.71 × 620.53
4. Step 4: Simplify right side
   1,117.89x = 957,302.46
5. Step 5: Solve for x
   x = 957,302.46/1,117.89
6. Step 6: Final answer
   x = 856.35