Finding the Third Proportional to 290,590.50 and 390,505.50

Step by Step Solution

1. Step 1: Write the proportion equation
   290,590.50 : 390,505.50 = 390,505.50 : x
2. Step 2: Convert to fraction form
   290,590.50/390,505.50 = 390,505.50/x
3. Step 3: Cross multiply
   290,590.50x = 390,505.50 × 390,505.50
4. Step 4: Simplify right side
   290,590.50x = 152,494,545,530.25
5. Step 5: Solve for x
   x = 152,494,545,530.25/290,590.50
6. Step 6: Final answer
   x = 524,774.71