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Finding the Fourth Proportional to 390.80, 539.37 and 297.40

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Solution

The fourth proportional to 390.80, 539.37 and 297.40 is: 410.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.80 : 539.37 = 297.40 : x
  2. Step 2: Convert to fraction form
    390.80/539.37 = 297.40/x
  3. Step 3: Cross multiply
    390.80x = 539.37 × 297.40
  4. Step 4: Simplify right side
    390.80x = 160,408.64
  5. Step 5: Solve for x
    x = 160,408.64/390.80
  6. Step 6: Final answer
    x = 410.46

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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.