Finding the Fourth Proportional to 3,945.34, 5,918.34 and 1,312.30

Step by Step Solution

1. Step 1: Write the proportion equation
   3,945.34 : 5,918.34 = 1,312.30 : x
2. Step 2: Convert to fraction form
   3,945.34/5,918.34 = 1,312.30/x
3. Step 3: Cross multiply
   3,945.34x = 5,918.34 × 1,312.30
4. Step 4: Simplify right side
   3,945.34x = 7,766,637.58
5. Step 5: Solve for x
   x = 7,766,637.58/3,945.34
6. Step 6: Final answer
   x = 1,968.56