Finding the Fourth Proportional to 1,390.46, 1,913.76 and 1,109.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.46 : 1,913.76 = 1,109.79 : x
2. Step 2: Convert to fraction form
   1,390.46/1,913.76 = 1,109.79/x
3. Step 3: Cross multiply
   1,390.46x = 1,913.76 × 1,109.79
4. Step 4: Simplify right side
   1,390.46x = 2,123,871.71
5. Step 5: Solve for x
   x = 2,123,871.71/1,390.46
6. Step 6: Final answer
   x = 1,527.47