Finding the Fourth Proportional to 111.61, 153.89 and 87.00

Step by Step Solution

1. Step 1: Write the proportion equation
   111.61 : 153.89 = 87.00 : x
2. Step 2: Convert to fraction form
   111.61/153.89 = 87.00/x
3. Step 3: Cross multiply
   111.61x = 153.89 × 87.00
4. Step 4: Simplify right side
   111.61x = 13,387.23
5. Step 5: Solve for x
   x = 13,387.23/111.61
6. Step 6: Final answer
   x = 119.95