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Finding the Fourth Proportional to 87.21, 130.23 and 86.67

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Solution

The fourth proportional to 87.21, 130.23 and 86.67 is: 129.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.21 : 130.23 = 86.67 : x
  2. Step 2: Convert to fraction form
    87.21/130.23 = 86.67/x
  3. Step 3: Cross multiply
    87.21x = 130.23 × 86.67
  4. Step 4: Simplify right side
    87.21x = 11,287.03
  5. Step 5: Solve for x
    x = 11,287.03/87.21
  6. Step 6: Final answer
    x = 129.42

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.