Finding the Fourth Proportional to 1,223.22, 1,688.88 and 830.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.22 : 1,688.88 = 830.10 : x
2. Step 2: Convert to fraction form
   1,223.22/1,688.88 = 830.10/x
3. Step 3: Cross multiply
   1,223.22x = 1,688.88 × 830.10
4. Step 4: Simplify right side
   1,223.22x = 1,401,939.29
5. Step 5: Solve for x
   x = 1,401,939.29/1,223.22
6. Step 6: Final answer
   x = 1,146.11