Finding the Fourth Proportional to 1,342.78, 1,855.56 and 970.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,342.78 : 1,855.56 = 970.90 : x
2. Step 2: Convert to fraction form
   1,342.78/1,855.56 = 970.90/x
3. Step 3: Cross multiply
   1,342.78x = 1,855.56 × 970.90
4. Step 4: Simplify right side
   1,342.78x = 1,801,563.20
5. Step 5: Solve for x
   x = 1,801,563.20/1,342.78
6. Step 6: Final answer
   x = 1,341.67