Finding the Fourth Proportional to 1,538.11, 2,121.46 and 978.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,538.11 : 2,121.46 = 978.10 : x
2. Step 2: Convert to fraction form
   1,538.11/2,121.46 = 978.10/x
3. Step 3: Cross multiply
   1,538.11x = 2,121.46 × 978.10
4. Step 4: Simplify right side
   1,538.11x = 2,075,000.03
5. Step 5: Solve for x
   x = 2,075,000.03/1,538.11
6. Step 6: Final answer
   x = 1,349.06