Finding the Fourth Proportional to 1,012.53, 1,396.59 and 619.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.53 : 1,396.59 = 619.74 : x
2. Step 2: Convert to fraction form
   1,012.53/1,396.59 = 619.74/x
3. Step 3: Cross multiply
   1,012.53x = 1,396.59 × 619.74
4. Step 4: Simplify right side
   1,012.53x = 865,522.69
5. Step 5: Solve for x
   x = 865,522.69/1,012.53
6. Step 6: Final answer
   x = 854.81