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Finding the Fourth Proportional to 77.50, 106.90 and 63.55

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Solution

The fourth proportional to 77.50, 106.90 and 63.55 is: 87.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.50 : 106.90 = 63.55 : x
  2. Step 2: Convert to fraction form
    77.50/106.90 = 63.55/x
  3. Step 3: Cross multiply
    77.50x = 106.90 × 63.55
  4. Step 4: Simplify right side
    77.50x = 6,793.50
  5. Step 5: Solve for x
    x = 6,793.50/77.50
  6. Step 6: Final answer
    x = 87.66

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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.