Finding the Fourth Proportional to 99.83, 137.73 and 64.86

Step by Step Solution

1. Step 1: Write the proportion equation
   99.83 : 137.73 = 64.86 : x
2. Step 2: Convert to fraction form
   99.83/137.73 = 64.86/x
3. Step 3: Cross multiply
   99.83x = 137.73 × 64.86
4. Step 4: Simplify right side
   99.83x = 8,933.17
5. Step 5: Solve for x
   x = 8,933.17/99.83
6. Step 6: Final answer
   x = 89.48