Finding the Fourth Proportional to 12,978.23, 19,455.66 and 4,656.29

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.23 : 19,455.66 = 4,656.29 : x
2. Step 2: Convert to fraction form
   12,978.23/19,455.66 = 4,656.29/x
3. Step 3: Cross multiply
   12,978.23x = 19,455.66 × 4,656.29
4. Step 4: Simplify right side
   12,978.23x = 90,591,097.82
5. Step 5: Solve for x
   x = 90,591,097.82/12,978.23
6. Step 6: Final answer
   x = 6,980.24