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Finding the Fourth Proportional to 390.61, 539.10 and 297.20

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Solution

The fourth proportional to 390.61, 539.10 and 297.20 is: 410.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.61 : 539.10 = 297.20 : x
  2. Step 2: Convert to fraction form
    390.61/539.10 = 297.20/x
  3. Step 3: Cross multiply
    390.61x = 539.10 × 297.20
  4. Step 4: Simplify right side
    390.61x = 160,220.52
  5. Step 5: Solve for x
    x = 160,220.52/390.61
  6. Step 6: Final answer
    x = 410.18

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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.