Finding the Fourth Proportional to 1,420.34, 2,131.72 and 690.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,420.34 : 2,131.72 = 690.53 : x
2. Step 2: Convert to fraction form
   1,420.34/2,131.72 = 690.53/x
3. Step 3: Cross multiply
   1,420.34x = 2,131.72 × 690.53
4. Step 4: Simplify right side
   1,420.34x = 1,472,004.23
5. Step 5: Solve for x
   x = 1,472,004.23/1,420.34
6. Step 6: Final answer
   x = 1,036.38