Finding the Fourth Proportional to 3,953.90, 5,928.89 and 1,320.50

Step by Step Solution

1. Step 1: Write the proportion equation
   3,953.90 : 5,928.89 = 1,320.50 : x
2. Step 2: Convert to fraction form
   3,953.90/5,928.89 = 1,320.50/x
3. Step 3: Cross multiply
   3,953.90x = 5,928.89 × 1,320.50
4. Step 4: Simplify right side
   3,953.90x = 7,829,117.37
5. Step 5: Solve for x
   x = 7,829,117.37/3,953.90
6. Step 6: Final answer
   x = 1,980.10