Finding the Fourth Proportional to 1,172.01, 1,615.15 and 839.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,172.01 : 1,615.15 = 839.86 : x
2. Step 2: Convert to fraction form
   1,172.01/1,615.15 = 839.86/x
3. Step 3: Cross multiply
   1,172.01x = 1,615.15 × 839.86
4. Step 4: Simplify right side
   1,172.01x = 1,356,499.88
5. Step 5: Solve for x
   x = 1,356,499.88/1,172.01
6. Step 6: Final answer
   x = 1,157.41