Finding the Fourth Proportional to 100.51, 150.86 and 83.57

Step by Step Solution

1. Step 1: Write the proportion equation
   100.51 : 150.86 = 83.57 : x
2. Step 2: Convert to fraction form
   100.51/150.86 = 83.57/x
3. Step 3: Cross multiply
   100.51x = 150.86 × 83.57
4. Step 4: Simplify right side
   100.51x = 12,606.82
5. Step 5: Solve for x
   x = 12,606.82/100.51
6. Step 6: Final answer
   x = 125.43