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Finding the Fourth Proportional to 479.73, 661.41 and 390.90

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Solution

The fourth proportional to 479.73, 661.41 and 390.90 is: 538.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    479.73 : 661.41 = 390.90 : x
  2. Step 2: Convert to fraction form
    479.73/661.41 = 390.90/x
  3. Step 3: Cross multiply
    479.73x = 661.41 × 390.90
  4. Step 4: Simplify right side
    479.73x = 258,545.17
  5. Step 5: Solve for x
    x = 258,545.17/479.73
  6. Step 6: Final answer
    x = 538.94

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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.