Finding the Fourth Proportional to 109.71, 151.25 and 85.10

Step by Step Solution

1. Step 1: Write the proportion equation
   109.71 : 151.25 = 85.10 : x
2. Step 2: Convert to fraction form
   109.71/151.25 = 85.10/x
3. Step 3: Cross multiply
   109.71x = 151.25 × 85.10
4. Step 4: Simplify right side
   109.71x = 12,870.19
5. Step 5: Solve for x
   x = 12,870.19/109.71
6. Step 6: Final answer
   x = 117.31