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Finding the Fourth Proportional to 76.66, 115.05 and 57.19

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Solution

The fourth proportional to 76.66, 115.05 and 57.19 is: 85.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.66 : 115.05 = 57.19 : x
  2. Step 2: Convert to fraction form
    76.66/115.05 = 57.19/x
  3. Step 3: Cross multiply
    76.66x = 115.05 × 57.19
  4. Step 4: Simplify right side
    76.66x = 6,579.13
  5. Step 5: Solve for x
    x = 6,579.13/76.66
  6. Step 6: Final answer
    x = 85.82

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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.