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Finding the Fourth Proportional to 387.81, 535.87 and 288.63

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Solution

The fourth proportional to 387.81, 535.87 and 288.63 is: 398.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.81 : 535.87 = 288.63 : x
  2. Step 2: Convert to fraction form
    387.81/535.87 = 288.63/x
  3. Step 3: Cross multiply
    387.81x = 535.87 × 288.63
  4. Step 4: Simplify right side
    387.81x = 154,665.48
  5. Step 5: Solve for x
    x = 154,665.48/387.81
  6. Step 6: Final answer
    x = 398.82

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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.