Finding the Fourth Proportional to 1,507.78, 2,080.74 and 983.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,507.78 : 2,080.74 = 983.81 : x
2. Step 2: Convert to fraction form
   1,507.78/2,080.74 = 983.81/x
3. Step 3: Cross multiply
   1,507.78x = 2,080.74 × 983.81
4. Step 4: Simplify right side
   1,507.78x = 2,047,061.71
5. Step 5: Solve for x
   x = 2,047,061.71/1,507.78
6. Step 6: Final answer
   x = 1,357.66