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Finding the Fourth Proportional to 487.72, 731.81 and 256.80

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Solution

The fourth proportional to 487.72, 731.81 and 256.80 is: 385.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    487.72 : 731.81 = 256.80 : x
  2. Step 2: Convert to fraction form
    487.72/731.81 = 256.80/x
  3. Step 3: Cross multiply
    487.72x = 731.81 × 256.80
  4. Step 4: Simplify right side
    487.72x = 187,929.45
  5. Step 5: Solve for x
    x = 187,929.45/487.72
  6. Step 6: Final answer
    x = 385.32

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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.