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Finding the Fourth Proportional to 76.81, 115.27 and 57.60

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Solution

The fourth proportional to 76.81, 115.27 and 57.60 is: 86.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.81 : 115.27 = 57.60 : x
  2. Step 2: Convert to fraction form
    76.81/115.27 = 57.60/x
  3. Step 3: Cross multiply
    76.81x = 115.27 × 57.60
  4. Step 4: Simplify right side
    76.81x = 6,639.55
  5. Step 5: Solve for x
    x = 6,639.55/76.81
  6. Step 6: Final answer
    x = 86.44

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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.