Finding the Fourth Proportional to 1,391.04, 1,917.18 and 970.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.04 : 1,917.18 = 970.05 : x
2. Step 2: Convert to fraction form
   1,391.04/1,917.18 = 970.05/x
3. Step 3: Cross multiply
   1,391.04x = 1,917.18 × 970.05
4. Step 4: Simplify right side
   1,391.04x = 1,859,760.46
5. Step 5: Solve for x
   x = 1,859,760.46/1,391.04
6. Step 6: Final answer
   x = 1,336.96