Finding the Fourth Proportional to 1,641.25, 2,264.72 and 978.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,641.25 : 2,264.72 = 978.17 : x
2. Step 2: Convert to fraction form
   1,641.25/2,264.72 = 978.17/x
3. Step 3: Cross multiply
   1,641.25x = 2,264.72 × 978.17
4. Step 4: Simplify right side
   1,641.25x = 2,215,281.93
5. Step 5: Solve for x
   x = 2,215,281.93/1,641.25
6. Step 6: Final answer
   x = 1,349.75