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Finding the Fourth Proportional to 515.76, 711.75 and 288.64

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Solution

The fourth proportional to 515.76, 711.75 and 288.64 is: 398.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.76 : 711.75 = 288.64 : x
  2. Step 2: Convert to fraction form
    515.76/711.75 = 288.64/x
  3. Step 3: Cross multiply
    515.76x = 711.75 × 288.64
  4. Step 4: Simplify right side
    515.76x = 205,439.52
  5. Step 5: Solve for x
    x = 205,439.52/515.76
  6. Step 6: Final answer
    x = 398.32

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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.