Finding the Fourth Proportional to 1,408.55, 2,111.60 and 542.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,408.55 : 2,111.60 = 542.25 : x
2. Step 2: Convert to fraction form
   1,408.55/2,111.60 = 542.25/x
3. Step 3: Cross multiply
   1,408.55x = 2,111.60 × 542.25
4. Step 4: Simplify right side
   1,408.55x = 1,145,016.46
5. Step 5: Solve for x
   x = 1,145,016.46/1,408.55
6. Step 6: Final answer
   x = 812.91