Finding the Fourth Proportional to 2,209.86, 3,315.15 and 670.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,209.86 : 3,315.15 = 670.50 : x
2. Step 2: Convert to fraction form
   2,209.86/3,315.15 = 670.50/x
3. Step 3: Cross multiply
   2,209.86x = 3,315.15 × 670.50
4. Step 4: Simplify right side
   2,209.86x = 2,222,808.08
5. Step 5: Solve for x
   x = 2,222,808.08/2,209.86
6. Step 6: Final answer
   x = 1,005.86