Finding the Fourth Proportional to 1,111.90, 1,666.18 and 879.84

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.90 : 1,666.18 = 879.84 : x
2. Step 2: Convert to fraction form
   1,111.90/1,666.18 = 879.84/x
3. Step 3: Cross multiply
   1,111.90x = 1,666.18 × 879.84
4. Step 4: Simplify right side
   1,111.90x = 1,465,971.81
5. Step 5: Solve for x
   x = 1,465,971.81/1,111.90
6. Step 6: Final answer
   x = 1,318.44