Finding the Third Proportional to 640,147.50 and 991,138

Step by Step Solution

1. Step 1: Write the proportion equation
   640,147.50 : 991,138 = 991,138 : x
2. Step 2: Convert to fraction form
   640,147.50/991,138 = 991,138/x
3. Step 3: Cross multiply
   640,147.50x = 991,138 × 991,138
4. Step 4: Simplify right side
   640,147.50x = 982,354,535,044
5. Step 5: Solve for x
   x = 982,354,535,044/640,147.50
6. Step 6: Final answer
   x = 1,534,575.29