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Finding the Fourth Proportional to 217.19, 325.91 and 87.21

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Solution

The fourth proportional to 217.19, 325.91 and 87.21 is: 130.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.19 : 325.91 = 87.21 : x
  2. Step 2: Convert to fraction form
    217.19/325.91 = 87.21/x
  3. Step 3: Cross multiply
    217.19x = 325.91 × 87.21
  4. Step 4: Simplify right side
    217.19x = 28,423.72
  5. Step 5: Solve for x
    x = 28,423.72/217.19
  6. Step 6: Final answer
    x = 130.87

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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.