Finding the Fourth Proportional to 99.84, 137.78 and 56.18

Step by Step Solution

1. Step 1: Write the proportion equation
   99.84 : 137.78 = 56.18 : x
2. Step 2: Convert to fraction form
   99.84/137.78 = 56.18/x
3. Step 3: Cross multiply
   99.84x = 137.78 × 56.18
4. Step 4: Simplify right side
   99.84x = 7,739.51
5. Step 5: Solve for x
   x = 7,739.51/99.84
6. Step 6: Final answer
   x = 77.52