Finding the Fourth Proportional to 1,415.72, 1,953.60 and 856.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,415.72 : 1,953.60 = 856.50 : x
2. Step 2: Convert to fraction form
   1,415.72/1,953.60 = 856.50/x
3. Step 3: Cross multiply
   1,415.72x = 1,953.60 × 856.50
4. Step 4: Simplify right side
   1,415.72x = 1,673,249.47
5. Step 5: Solve for x
   x = 1,673,249.47/1,415.72
6. Step 6: Final answer
   x = 1,181.91