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Finding the Fourth Proportional to 500.20, 689.55 and 389.45

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Solution

The fourth proportional to 500.20, 689.55 and 389.45 is: 536.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    500.20 : 689.55 = 389.45 : x
  2. Step 2: Convert to fraction form
    500.20/689.55 = 389.45/x
  3. Step 3: Cross multiply
    500.20x = 689.55 × 389.45
  4. Step 4: Simplify right side
    500.20x = 268,545.25
  5. Step 5: Solve for x
    x = 268,545.25/500.20
  6. Step 6: Final answer
    x = 536.88

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.