Finding the Fourth Proportional to 1,216.22, 1,821.69 and 637.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,216.22 : 1,821.69 = 637.88 : x
2. Step 2: Convert to fraction form
   1,216.22/1,821.69 = 637.88/x
3. Step 3: Cross multiply
   1,216.22x = 1,821.69 × 637.88
4. Step 4: Simplify right side
   1,216.22x = 1,162,010.51
5. Step 5: Solve for x
   x = 1,162,010.51/1,216.22
6. Step 6: Final answer
   x = 955.43