Finding the Fourth Proportional to 1,059.87, 1,578.86 and 992.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,059.87 : 1,578.86 = 992.59 : x
2. Step 2: Convert to fraction form
   1,059.87/1,578.86 = 992.59/x
3. Step 3: Cross multiply
   1,059.87x = 1,578.86 × 992.59
4. Step 4: Simplify right side
   1,059.87x = 1,567,160.65
5. Step 5: Solve for x
   x = 1,567,160.65/1,059.87
6. Step 6: Final answer
   x = 1,478.63