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Finding the Fourth Proportional to 349.20, 523.80 and 257.40

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Solution

The fourth proportional to 349.20, 523.80 and 257.40 is: 386.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    349.20 : 523.80 = 257.40 : x
  2. Step 2: Convert to fraction form
    349.20/523.80 = 257.40/x
  3. Step 3: Cross multiply
    349.20x = 523.80 × 257.40
  4. Step 4: Simplify right side
    349.20x = 134,826.12
  5. Step 5: Solve for x
    x = 134,826.12/349.20
  6. Step 6: Final answer
    x = 386.10

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.