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Finding the Fourth Proportional to 87.56, 120.84 and 64.34

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Solution

The fourth proportional to 87.56, 120.84 and 64.34 is: 88.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.56 : 120.84 = 64.34 : x
  2. Step 2: Convert to fraction form
    87.56/120.84 = 64.34/x
  3. Step 3: Cross multiply
    87.56x = 120.84 × 64.34
  4. Step 4: Simplify right side
    87.56x = 7,774.85
  5. Step 5: Solve for x
    x = 7,774.85/87.56
  6. Step 6: Final answer
    x = 88.79

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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.