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Finding the Fourth Proportional to 80.61, 120.85 and 64.55

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Solution

The fourth proportional to 80.61, 120.85 and 64.55 is: 96.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.61 : 120.85 = 64.55 : x
  2. Step 2: Convert to fraction form
    80.61/120.85 = 64.55/x
  3. Step 3: Cross multiply
    80.61x = 120.85 × 64.55
  4. Step 4: Simplify right side
    80.61x = 7,800.51
  5. Step 5: Solve for x
    x = 7,800.51/80.61
  6. Step 6: Final answer
    x = 96.77

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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.