Finding the Fourth Proportional to 1,012.58, 1,396.83 and 619.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.58 : 1,396.83 = 619.34 : x
2. Step 2: Convert to fraction form
   1,012.58/1,396.83 = 619.34/x
3. Step 3: Cross multiply
   1,012.58x = 1,396.83 × 619.34
4. Step 4: Simplify right side
   1,012.58x = 865,112.69
5. Step 5: Solve for x
   x = 865,112.69/1,012.58
6. Step 6: Final answer
   x = 854.36