Finding the Fourth Proportional to 139,061.15, 191,833.74 and 87,987.81

Step by Step Solution

1. Step 1: Write the proportion equation
   139,061.15 : 191,833.74 = 87,987.81 : x
2. Step 2: Convert to fraction form
   139,061.15/191,833.74 = 87,987.81/x
3. Step 3: Cross multiply
   139,061.15x = 191,833.74 × 87,987.81
4. Step 4: Simplify right side
   139,061.15x = 16,879,030,666.71
5. Step 5: Solve for x
   x = 16,879,030,666.71/139,061.15
6. Step 6: Final answer
   x = 121,378.48