Finding the Fourth Proportional to 101.42, 139.78 and 100.00

Step by Step Solution

1. Step 1: Write the proportion equation
   101.42 : 139.78 = 100.00 : x
2. Step 2: Convert to fraction form
   101.42/139.78 = 100.00/x
3. Step 3: Cross multiply
   101.42x = 139.78 × 100.00
4. Step 4: Simplify right side
   101.42x = 13,977.74
5. Step 5: Solve for x
   x = 13,977.74/101.42
6. Step 6: Final answer
   x = 137.82