Finding the Fourth Proportional to 1,312.10, 1,810.69 and 977.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,312.10 : 1,810.69 = 977.50 : x
2. Step 2: Convert to fraction form
   1,312.10/1,810.69 = 977.50/x
3. Step 3: Cross multiply
   1,312.10x = 1,810.69 × 977.50
4. Step 4: Simplify right side
   1,312.10x = 1,769,949.29
5. Step 5: Solve for x
   x = 1,769,949.29/1,312.10
6. Step 6: Final answer
   x = 1,348.95