Finding the Fourth Proportional to 1,415.90, 1,953.98 and 856.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,415.90 : 1,953.98 = 856.25 : x
2. Step 2: Convert to fraction form
   1,415.90/1,953.98 = 856.25/x
3. Step 3: Cross multiply
   1,415.90x = 1,953.98 × 856.25
4. Step 4: Simplify right side
   1,415.90x = 1,673,095.38
5. Step 5: Solve for x
   x = 1,673,095.38/1,415.90
6. Step 6: Final answer
   x = 1,181.65