Home / 1,139.10-1,708.20-408.30

Finding the Fourth Proportional to 1,139.10, 1,708.20 and 408.30

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Solution

The fourth proportional to 1,139.10, 1,708.20 and 408.30 is: 612.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,139.10 : 1,708.20 = 408.30 : x
  2. Step 2: Convert to fraction form
    1,139.10/1,708.20 = 408.30/x
  3. Step 3: Cross multiply
    1,139.10x = 1,708.20 × 408.30
  4. Step 4: Simplify right side
    1,139.10x = 697,458.06
  5. Step 5: Solve for x
    x = 697,458.06/1,139.10
  6. Step 6: Final answer
    x = 612.29

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.