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Finding the Fourth Proportional to 387.71, 535.19 and 256.90

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Solution

The fourth proportional to 387.71, 535.19 and 256.90 is: 354.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.71 : 535.19 = 256.90 : x
  2. Step 2: Convert to fraction form
    387.71/535.19 = 256.90/x
  3. Step 3: Cross multiply
    387.71x = 535.19 × 256.90
  4. Step 4: Simplify right side
    387.71x = 137,490.31
  5. Step 5: Solve for x
    x = 137,490.31/387.71
  6. Step 6: Final answer
    x = 354.62

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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.