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Finding the Fourth Proportional to 257.08, 387.36 and 212.43

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Solution

The fourth proportional to 257.08, 387.36 and 212.43 is: 320.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.08 : 387.36 = 212.43 : x
  2. Step 2: Convert to fraction form
    257.08/387.36 = 212.43/x
  3. Step 3: Cross multiply
    257.08x = 387.36 × 212.43
  4. Step 4: Simplify right side
    257.08x = 82,285.82
  5. Step 5: Solve for x
    x = 82,285.82/257.08
  6. Step 6: Final answer
    x = 320.08

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.