Finding the Fourth Proportional to 99.29, 137.00 and 78.60

Step by Step Solution

1. Step 1: Write the proportion equation
   99.29 : 137.00 = 78.60 : x
2. Step 2: Convert to fraction form
   99.29/137.00 = 78.60/x
3. Step 3: Cross multiply
   99.29x = 137.00 × 78.60
4. Step 4: Simplify right side
   99.29x = 10,767.81
5. Step 5: Solve for x
   x = 10,767.81/99.29
6. Step 6: Final answer
   x = 108.45