Finding the Fourth Proportional to 191,621.40, 287,081.82 and 138,900.12

Step by Step Solution

1. Step 1: Write the proportion equation
   191,621.40 : 287,081.82 = 138,900.12 : x
2. Step 2: Convert to fraction form
   191,621.40/287,081.82 = 138,900.12/x
3. Step 3: Cross multiply
   191,621.40x = 287,081.82 × 138,900.12
4. Step 4: Simplify right side
   191,621.40x = 39,875,699,247.82
5. Step 5: Solve for x
   x = 39,875,699,247.82/191,621.40
6. Step 6: Final answer
   x = 208,096.27