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Finding the Fourth Proportional to 217.11, 325.71 and 87.15

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Solution

The fourth proportional to 217.11, 325.71 and 87.15 is: 130.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.11 : 325.71 = 87.15 : x
  2. Step 2: Convert to fraction form
    217.11/325.71 = 87.15/x
  3. Step 3: Cross multiply
    217.11x = 325.71 × 87.15
  4. Step 4: Simplify right side
    217.11x = 28,385.63
  5. Step 5: Solve for x
    x = 28,385.63/217.11
  6. Step 6: Final answer
    x = 130.74

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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.