Finding the Fourth Proportional to 1,420.04, 2,128.17 and 688.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,420.04 : 2,128.17 = 688.16 : x
2. Step 2: Convert to fraction form
   1,420.04/2,128.17 = 688.16/x
3. Step 3: Cross multiply
   1,420.04x = 2,128.17 × 688.16
4. Step 4: Simplify right side
   1,420.04x = 1,464,521.47
5. Step 5: Solve for x
   x = 1,464,521.47/1,420.04
6. Step 6: Final answer
   x = 1,031.32