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Finding the Fourth Proportional to 77.89, 117 and 57.72

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Solution

The fourth proportional to 77.89, 117 and 57.72 is: 86.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.89 : 117 = 57.72 : x
  2. Step 2: Convert to fraction form
    77.89/117 = 57.72/x
  3. Step 3: Cross multiply
    77.89x = 117 × 57.72
  4. Step 4: Simplify right side
    77.89x = 6,753.02
  5. Step 5: Solve for x
    x = 6,753.02/77.89
  6. Step 6: Final answer
    x = 86.70

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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.