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Finding the Fourth Proportional to 718.20, 1,077.28 and 389.28

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Solution

The fourth proportional to 718.20, 1,077.28 and 389.28 is: 583.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.20 : 1,077.28 = 389.28 : x
  2. Step 2: Convert to fraction form
    718.20/1,077.28 = 389.28/x
  3. Step 3: Cross multiply
    718.20x = 1,077.28 × 389.28
  4. Step 4: Simplify right side
    718.20x = 419,363.56
  5. Step 5: Solve for x
    x = 419,363.56/718.20
  6. Step 6: Final answer
    x = 583.91

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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.