Finding the Fourth Proportional to 1,413.86, 2,115.59 and 856.58

Step by Step Solution

1. Step 1: Write the proportion equation
   1,413.86 : 2,115.59 = 856.58 : x
2. Step 2: Convert to fraction form
   1,413.86/2,115.59 = 856.58/x
3. Step 3: Cross multiply
   1,413.86x = 2,115.59 × 856.58
4. Step 4: Simplify right side
   1,413.86x = 1,812,157.22
5. Step 5: Solve for x
   x = 1,812,157.22/1,413.86
6. Step 6: Final answer
   x = 1,281.71