Finding the Fourth Proportional to 91,301.80, 136,967.42 and 28,121.91

Step by Step Solution

1. Step 1: Write the proportion equation
   91,301.80 : 136,967.42 = 28,121.91 : x
2. Step 2: Convert to fraction form
   91,301.80/136,967.42 = 28,121.91/x
3. Step 3: Cross multiply
   91,301.80x = 136,967.42 × 28,121.91
4. Step 4: Simplify right side
   91,301.80x = 3,851,785,458.17
5. Step 5: Solve for x
   x = 3,851,785,458.17/91,301.80
6. Step 6: Final answer
   x = 42,187.40