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Finding the Fourth Proportional to 390.52, 585.30 and 217.18

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Solution

The fourth proportional to 390.52, 585.30 and 217.18 is: 325.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.52 : 585.30 = 217.18 : x
  2. Step 2: Convert to fraction form
    390.52/585.30 = 217.18/x
  3. Step 3: Cross multiply
    390.52x = 585.30 × 217.18
  4. Step 4: Simplify right side
    390.52x = 127,115.45
  5. Step 5: Solve for x
    x = 127,115.45/390.52
  6. Step 6: Final answer
    x = 325.50

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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.