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Finding the Fourth Proportional to 348.20, 521.28 and 257.30

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Solution

The fourth proportional to 348.20, 521.28 and 257.30 is: 385.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    348.20 : 521.28 = 257.30 : x
  2. Step 2: Convert to fraction form
    348.20/521.28 = 257.30/x
  3. Step 3: Cross multiply
    348.20x = 521.28 × 257.30
  4. Step 4: Simplify right side
    348.20x = 134,125.36
  5. Step 5: Solve for x
    x = 134,125.36/348.20
  6. Step 6: Final answer
    x = 385.20

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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.