Finding the Fourth Proportional to 1,415.90, 1,953.78 and 856.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,415.90 : 1,953.78 = 856.46 : x
2. Step 2: Convert to fraction form
   1,415.90/1,953.78 = 856.46/x
3. Step 3: Cross multiply
   1,415.90x = 1,953.78 × 856.46
4. Step 4: Simplify right side
   1,415.90x = 1,673,334.42
5. Step 5: Solve for x
   x = 1,673,334.42/1,415.90
6. Step 6: Final answer
   x = 1,181.82