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Finding the Fourth Proportional to 387.20, 581.16 and 279.20

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Solution

The fourth proportional to 387.20, 581.16 and 279.20 is: 419.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.20 : 581.16 = 279.20 : x
  2. Step 2: Convert to fraction form
    387.20/581.16 = 279.20/x
  3. Step 3: Cross multiply
    387.20x = 581.16 × 279.20
  4. Step 4: Simplify right side
    387.20x = 162,259.87
  5. Step 5: Solve for x
    x = 162,259.87/387.20
  6. Step 6: Final answer
    x = 419.06

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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.