Finding the Fourth Proportional to 1,012.68, 1,396.71 and 619.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.68 : 1,396.71 = 619.56 : x
2. Step 2: Convert to fraction form
   1,012.68/1,396.71 = 619.56/x
3. Step 3: Cross multiply
   1,012.68x = 1,396.71 × 619.56
4. Step 4: Simplify right side
   1,012.68x = 865,345.65
5. Step 5: Solve for x
   x = 865,345.65/1,012.68
6. Step 6: Final answer
   x = 854.51