Finding the Fourth Proportional to 1,012.59, 1,397.31 and 619.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.59 : 1,397.31 = 619.53 : x
2. Step 2: Convert to fraction form
   1,012.59/1,397.31 = 619.53/x
3. Step 3: Cross multiply
   1,012.59x = 1,397.31 × 619.53
4. Step 4: Simplify right side
   1,012.59x = 865,675.46
5. Step 5: Solve for x
   x = 865,675.46/1,012.59
6. Step 6: Final answer
   x = 854.91