Finding the Third Proportional to 191,107.50 and 287,139

Step by Step Solution

1. Step 1: Write the proportion equation
   191,107.50 : 287,139 = 287,139 : x
2. Step 2: Convert to fraction form
   191,107.50/287,139 = 287,139/x
3. Step 3: Cross multiply
   191,107.50x = 287,139 × 287,139
4. Step 4: Simplify right side
   191,107.50x = 82,448,805,321
5. Step 5: Solve for x
   x = 82,448,805,321/191,107.50
6. Step 6: Final answer
   x = 431,426.32