Finding the Fourth Proportional to 7,172.40, 10,758.31 and 1,978.14

Step by Step Solution

1. Step 1: Write the proportion equation
   7,172.40 : 10,758.31 = 1,978.14 : x
2. Step 2: Convert to fraction form
   7,172.40/10,758.31 = 1,978.14/x
3. Step 3: Cross multiply
   7,172.40x = 10,758.31 × 1,978.14
4. Step 4: Simplify right side
   7,172.40x = 21,281,443.34
5. Step 5: Solve for x
   x = 21,281,443.34/7,172.40
6. Step 6: Final answer
   x = 2,967.13