Finding the Fourth Proportional to 1,373.10, 2,054.79 and 1,290.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,373.10 : 2,054.79 = 1,290.12 : x
2. Step 2: Convert to fraction form
   1,373.10/2,054.79 = 1,290.12/x
3. Step 3: Cross multiply
   1,373.10x = 2,054.79 × 1,290.12
4. Step 4: Simplify right side
   1,373.10x = 2,650,925.67
5. Step 5: Solve for x
   x = 2,650,925.67/1,373.10
6. Step 6: Final answer
   x = 1,930.61