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Finding the Fourth Proportional to 76.86, 115.08 and 55.14

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Solution

The fourth proportional to 76.86, 115.08 and 55.14 is: 82.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.86 : 115.08 = 55.14 : x
  2. Step 2: Convert to fraction form
    76.86/115.08 = 55.14/x
  3. Step 3: Cross multiply
    76.86x = 115.08 × 55.14
  4. Step 4: Simplify right side
    76.86x = 6,345.51
  5. Step 5: Solve for x
    x = 6,345.51/76.86
  6. Step 6: Final answer
    x = 82.56

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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.