Finding the Fourth Proportional to 1,607.05, 2,215.16 and 1,311.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,607.05 : 2,215.16 = 1,311.81 : x
2. Step 2: Convert to fraction form
   1,607.05/2,215.16 = 1,311.81/x
3. Step 3: Cross multiply
   1,607.05x = 2,215.16 × 1,311.81
4. Step 4: Simplify right side
   1,607.05x = 2,905,869.04
5. Step 5: Solve for x
   x = 2,905,869.04/1,607.05
6. Step 6: Final answer
   x = 1,808.20