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Finding the Fourth Proportional to 87.64, 120.98 and 56.56

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Solution

The fourth proportional to 87.64, 120.98 and 56.56 is: 78.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.64 : 120.98 = 56.56 : x
  2. Step 2: Convert to fraction form
    87.64/120.98 = 56.56/x
  3. Step 3: Cross multiply
    87.64x = 120.98 × 56.56
  4. Step 4: Simplify right side
    87.64x = 6,842.63
  5. Step 5: Solve for x
    x = 6,842.63/87.64
  6. Step 6: Final answer
    x = 78.08

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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.