Finding the Fourth Proportional to 1,144.86, 1,579.91 and 620.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,144.86 : 1,579.91 = 620.89 : x
2. Step 2: Convert to fraction form
   1,144.86/1,579.91 = 620.89/x
3. Step 3: Cross multiply
   1,144.86x = 1,579.91 × 620.89
4. Step 4: Simplify right side
   1,144.86x = 980,950.32
5. Step 5: Solve for x
   x = 980,950.32/1,144.86
6. Step 6: Final answer
   x = 856.83