Finding the Fourth Proportional to 1,106.72, 1,658.80 and 978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,106.72 : 1,658.80 = 978.72 : x
2. Step 2: Convert to fraction form
   1,106.72/1,658.80 = 978.72/x
3. Step 3: Cross multiply
   1,106.72x = 1,658.80 × 978.72
4. Step 4: Simplify right side
   1,106.72x = 1,623,500.74
5. Step 5: Solve for x
   x = 1,623,500.74/1,106.72
6. Step 6: Final answer
   x = 1,466.95