Finding the Fourth Proportional to 1,381.71, 2,069.96 and 688.01

Step by Step Solution

1. Step 1: Write the proportion equation
   1,381.71 : 2,069.96 = 688.01 : x
2. Step 2: Convert to fraction form
   1,381.71/2,069.96 = 688.01/x
3. Step 3: Cross multiply
   1,381.71x = 2,069.96 × 688.01
4. Step 4: Simplify right side
   1,381.71x = 1,424,139.39
5. Step 5: Solve for x
   x = 1,424,139.39/1,381.71
6. Step 6: Final answer
   x = 1,030.71