Finding the Fourth Proportional to 1,569.50, 2,355.38 and 645.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,569.50 : 2,355.38 = 645.12 : x
2. Step 2: Convert to fraction form
   1,569.50/2,355.38 = 645.12/x
3. Step 3: Cross multiply
   1,569.50x = 2,355.38 × 645.12
4. Step 4: Simplify right side
   1,569.50x = 1,519,499.52
5. Step 5: Solve for x
   x = 1,519,499.52/1,569.50
6. Step 6: Final answer
   x = 968.15