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Finding the Fourth Proportional to 385.18, 531.28 and 280.16

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Solution

The fourth proportional to 385.18, 531.28 and 280.16 is: 386.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.18 : 531.28 = 280.16 : x
  2. Step 2: Convert to fraction form
    385.18/531.28 = 280.16/x
  3. Step 3: Cross multiply
    385.18x = 531.28 × 280.16
  4. Step 4: Simplify right side
    385.18x = 148,843.40
  5. Step 5: Solve for x
    x = 148,843.40/385.18
  6. Step 6: Final answer
    x = 386.43

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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.