Finding the Fourth Proportional to 1,641.06, 2,264.76 and 978.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,641.06 : 2,264.76 = 978.08 : x
2. Step 2: Convert to fraction form
   1,641.06/2,264.76 = 978.08/x
3. Step 3: Cross multiply
   1,641.06x = 2,264.76 × 978.08
4. Step 4: Simplify right side
   1,641.06x = 2,215,105.14
5. Step 5: Solve for x
   x = 2,215,105.14/1,641.06
6. Step 6: Final answer
   x = 1,349.80