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Finding the Fourth Proportional to 387.31, 534.30 and 256.09

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Solution

The fourth proportional to 387.31, 534.30 and 256.09 is: 353.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.31 : 534.30 = 256.09 : x
  2. Step 2: Convert to fraction form
    387.31/534.30 = 256.09/x
  3. Step 3: Cross multiply
    387.31x = 534.30 × 256.09
  4. Step 4: Simplify right side
    387.31x = 136,828.89
  5. Step 5: Solve for x
    x = 136,828.89/387.31
  6. Step 6: Final answer
    x = 353.28

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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.