Finding the Fourth Proportional to 1,012.86, 1,515.33 and 688.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.86 : 1,515.33 = 688.50 : x
2. Step 2: Convert to fraction form
   1,012.86/1,515.33 = 688.50/x
3. Step 3: Cross multiply
   1,012.86x = 1,515.33 × 688.50
4. Step 4: Simplify right side
   1,012.86x = 1,043,304.71
5. Step 5: Solve for x
   x = 1,043,304.71/1,012.86
6. Step 6: Final answer
   x = 1,030.06