Finding the Fourth Proportional to 1,642.54, 2,265.54 and 978.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,642.54 : 2,265.54 = 978.88 : x
2. Step 2: Convert to fraction form
   1,642.54/2,265.54 = 978.88/x
3. Step 3: Cross multiply
   1,642.54x = 2,265.54 × 978.88
4. Step 4: Simplify right side
   1,642.54x = 2,217,691.80
5. Step 5: Solve for x
   x = 2,217,691.80/1,642.54
6. Step 6: Final answer
   x = 1,350.16