Finding the Fourth Proportional to 1,390.91, 1,918.49 and 948.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.91 : 1,918.49 = 948.06 : x
2. Step 2: Convert to fraction form
   1,390.91/1,918.49 = 948.06/x
3. Step 3: Cross multiply
   1,390.91x = 1,918.49 × 948.06
4. Step 4: Simplify right side
   1,390.91x = 1,818,838.89
5. Step 5: Solve for x
   x = 1,818,838.89/1,390.91
6. Step 6: Final answer
   x = 1,307.67