Finding the Fourth Proportional to 1,445.86, 1,994.61 and 856.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,445.86 : 1,994.61 = 856.39 : x
2. Step 2: Convert to fraction form
   1,445.86/1,994.61 = 856.39/x
3. Step 3: Cross multiply
   1,445.86x = 1,994.61 × 856.39
4. Step 4: Simplify right side
   1,445.86x = 1,708,164.06
5. Step 5: Solve for x
   x = 1,708,164.06/1,445.86
6. Step 6: Final answer
   x = 1,181.42