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Finding the Fourth Proportional to 398.10, 548.64 and 391.08

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Solution

The fourth proportional to 398.10, 548.64 and 391.08 is: 538.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.10 : 548.64 = 391.08 : x
  2. Step 2: Convert to fraction form
    398.10/548.64 = 391.08/x
  3. Step 3: Cross multiply
    398.10x = 548.64 × 391.08
  4. Step 4: Simplify right side
    398.10x = 214,562.13
  5. Step 5: Solve for x
    x = 214,562.13/398.10
  6. Step 6: Final answer
    x = 538.97

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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.