Finding the Fourth Proportional to 1,428.59, 2,140.80 and 697.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.59 : 2,140.80 = 697.34 : x
2. Step 2: Convert to fraction form
   1,428.59/2,140.80 = 697.34/x
3. Step 3: Cross multiply
   1,428.59x = 2,140.80 × 697.34
4. Step 4: Simplify right side
   1,428.59x = 1,492,854.77
5. Step 5: Solve for x
   x = 1,492,854.77/1,428.59
6. Step 6: Final answer
   x = 1,044.99