Finding the Fourth Proportional to 1,012.18, 1,396.56 and 619.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.18 : 1,396.56 = 619.06 : x
2. Step 2: Convert to fraction form
   1,012.18/1,396.56 = 619.06/x
3. Step 3: Cross multiply
   1,012.18x = 1,396.56 × 619.06
4. Step 4: Simplify right side
   1,012.18x = 864,554.43
5. Step 5: Solve for x
   x = 864,554.43/1,012.18
6. Step 6: Final answer
   x = 854.15