Finding the Fourth Proportional to 1,215.21, 1,821.72 and 565.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,215.21 : 1,821.72 = 565.59 : x
2. Step 2: Convert to fraction form
   1,215.21/1,821.72 = 565.59/x
3. Step 3: Cross multiply
   1,215.21x = 1,821.72 × 565.59
4. Step 4: Simplify right side
   1,215.21x = 1,030,346.61
5. Step 5: Solve for x
   x = 1,030,346.61/1,215.21
6. Step 6: Final answer
   x = 847.88