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Finding the Fourth Proportional to 398.31, 549.75 and 280.86

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Solution

The fourth proportional to 398.31, 549.75 and 280.86 is: 387.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.31 : 549.75 = 280.86 : x
  2. Step 2: Convert to fraction form
    398.31/549.75 = 280.86/x
  3. Step 3: Cross multiply
    398.31x = 549.75 × 280.86
  4. Step 4: Simplify right side
    398.31x = 154,402.79
  5. Step 5: Solve for x
    x = 154,402.79/398.31
  6. Step 6: Final answer
    x = 387.64

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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.