Finding the Fourth Proportional to 78,781.42, 108,718.70 and 42,972.20

Step by Step Solution

1. Step 1: Write the proportion equation
   78,781.42 : 108,718.70 = 42,972.20 : x
2. Step 2: Convert to fraction form
   78,781.42/108,718.70 = 42,972.20/x
3. Step 3: Cross multiply
   78,781.42x = 108,718.70 × 42,972.20
4. Step 4: Simplify right side
   78,781.42x = 4,671,881,505.28
5. Step 5: Solve for x
   x = 4,671,881,505.28/78,781.42
6. Step 6: Final answer
   x = 59,301.82