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Finding the Fourth Proportional to 389.72, 537.89 and 256.71

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Solution

The fourth proportional to 389.72, 537.89 and 256.71 is: 354.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.72 : 537.89 = 256.71 : x
  2. Step 2: Convert to fraction form
    389.72/537.89 = 256.71/x
  3. Step 3: Cross multiply
    389.72x = 537.89 × 256.71
  4. Step 4: Simplify right side
    389.72x = 138,081.74
  5. Step 5: Solve for x
    x = 138,081.74/389.72
  6. Step 6: Final answer
    x = 354.31

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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.