Finding the Third Proportional to 542.50 and 1,139

Step by Step Solution

1. Step 1: Write the proportion equation
   542.50 : 1,139 = 1,139 : x
2. Step 2: Convert to fraction form
   542.50/1,139 = 1,139/x
3. Step 3: Cross multiply
   542.50x = 1,139 × 1,139
4. Step 4: Simplify right side
   542.50x = 1,297,321
5. Step 5: Solve for x
   x = 1,297,321/542.50
6. Step 6: Final answer
   x = 2,391.38