Finding the Fourth Proportional to 2,663.33, 3,988.80 and 1,272.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,663.33 : 3,988.80 = 1,272.20 : x
2. Step 2: Convert to fraction form
   2,663.33/3,988.80 = 1,272.20/x
3. Step 3: Cross multiply
   2,663.33x = 3,988.80 × 1,272.20
4. Step 4: Simplify right side
   2,663.33x = 5,074,531.42
5. Step 5: Solve for x
   x = 5,074,531.42/2,663.33
6. Step 6: Final answer
   x = 1,905.34