Finding the Fourth Proportional to 31,146, 42,987.34 and 19,509.60

Step by Step Solution

1. Step 1: Write the proportion equation
   31,146 : 42,987.34 = 19,509.60 : x
2. Step 2: Convert to fraction form
   31,146/42,987.34 = 19,509.60/x
3. Step 3: Cross multiply
   31,146x = 42,987.34 × 19,509.60
4. Step 4: Simplify right side
   31,146x = 838,665,808.46
5. Step 5: Solve for x
   x = 838,665,808.46/31,146
6. Step 6: Final answer
   x = 26,926.92