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Finding the Fourth Proportional to 385.20, 531.36 and 280.17

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Solution

The fourth proportional to 385.20, 531.36 and 280.17 is: 386.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.20 : 531.36 = 280.17 : x
  2. Step 2: Convert to fraction form
    385.20/531.36 = 280.17/x
  3. Step 3: Cross multiply
    385.20x = 531.36 × 280.17
  4. Step 4: Simplify right side
    385.20x = 148,871.13
  5. Step 5: Solve for x
    x = 148,871.13/385.20
  6. Step 6: Final answer
    x = 386.48

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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.