Finding the Fourth Proportional to 1,978.47, 2,966.67 and 990.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.47 : 2,966.67 = 990.23 : x
2. Step 2: Convert to fraction form
   1,978.47/2,966.67 = 990.23/x
3. Step 3: Cross multiply
   1,978.47x = 2,966.67 × 990.23
4. Step 4: Simplify right side
   1,978.47x = 2,937,670.80
5. Step 5: Solve for x
   x = 2,937,670.80/1,978.47
6. Step 6: Final answer
   x = 1,484.82