Finding the Fourth Proportional to 100.59, 150.60 and 90.99

Step by Step Solution

1. Step 1: Write the proportion equation
   100.59 : 150.60 = 90.99 : x
2. Step 2: Convert to fraction form
   100.59/150.60 = 90.99/x
3. Step 3: Cross multiply
   100.59x = 150.60 × 90.99
4. Step 4: Simplify right side
   100.59x = 13,701.89
5. Step 5: Solve for x
   x = 13,701.89/100.59
6. Step 6: Final answer
   x = 136.22