Finding the Fourth Proportional to 99.88, 137.82 and 61.12

Step by Step Solution

1. Step 1: Write the proportion equation
   99.88 : 137.82 = 61.12 : x
2. Step 2: Convert to fraction form
   99.88/137.82 = 61.12/x
3. Step 3: Cross multiply
   99.88x = 137.82 × 61.12
4. Step 4: Simplify right side
   99.88x = 8,423.56
5. Step 5: Solve for x
   x = 8,423.56/99.88
6. Step 6: Final answer
   x = 84.34