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Finding the Fourth Proportional to 398.83, 549.64 and 391.74

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Solution

The fourth proportional to 398.83, 549.64 and 391.74 is: 539.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.83 : 549.64 = 391.74 : x
  2. Step 2: Convert to fraction form
    398.83/549.64 = 391.74/x
  3. Step 3: Cross multiply
    398.83x = 549.64 × 391.74
  4. Step 4: Simplify right side
    398.83x = 215,315.97
  5. Step 5: Solve for x
    x = 215,315.97/398.83
  6. Step 6: Final answer
    x = 539.87

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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.