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Finding the Fourth Proportional to 77.10, 115.50 and 57.86

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Solution

The fourth proportional to 77.10, 115.50 and 57.86 is: 86.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.10 : 115.50 = 57.86 : x
  2. Step 2: Convert to fraction form
    77.10/115.50 = 57.86/x
  3. Step 3: Cross multiply
    77.10x = 115.50 × 57.86
  4. Step 4: Simplify right side
    77.10x = 6,682.74
  5. Step 5: Solve for x
    x = 6,682.74/77.10
  6. Step 6: Final answer
    x = 86.68

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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.