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Finding the Fourth Proportional to 424.80, 636.42 and 257.76

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Solution

The fourth proportional to 424.80, 636.42 and 257.76 is: 386.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    424.80 : 636.42 = 257.76 : x
  2. Step 2: Convert to fraction form
    424.80/636.42 = 257.76/x
  3. Step 3: Cross multiply
    424.80x = 636.42 × 257.76
  4. Step 4: Simplify right side
    424.80x = 164,043.62
  5. Step 5: Solve for x
    x = 164,043.62/424.80
  6. Step 6: Final answer
    x = 386.17

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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.