Finding the Fourth Proportional to 12,978.42, 19,438.44 and 9,100.14

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.42 : 19,438.44 = 9,100.14 : x
2. Step 2: Convert to fraction form
   12,978.42/19,438.44 = 9,100.14/x
3. Step 3: Cross multiply
   12,978.42x = 19,438.44 × 9,100.14
4. Step 4: Simplify right side
   12,978.42x = 176,892,525.38
5. Step 5: Solve for x
   x = 176,892,525.38/12,978.42
6. Step 6: Final answer
   x = 13,629.74