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Finding the Fourth Proportional to 387, 580.79 and 256.96

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Solution

The fourth proportional to 387, 580.79 and 256.96 is: 385.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    387 : 580.79 = 256.96 : x
  2. Step 2: Convert to fraction form
    387/580.79 = 256.96/x
  3. Step 3: Cross multiply
    387x = 580.79 × 256.96
  4. Step 4: Simplify right side
    387x = 149,241.17
  5. Step 5: Solve for x
    x = 149,241.17/387
  6. Step 6: Final answer
    x = 385.64

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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.