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Finding the Fourth Proportional to 76.77, 115.58 and 67.20

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Solution

The fourth proportional to 76.77, 115.58 and 67.20 is: 101.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.77 : 115.58 = 67.20 : x
  2. Step 2: Convert to fraction form
    76.77/115.58 = 67.20/x
  3. Step 3: Cross multiply
    76.77x = 115.58 × 67.20
  4. Step 4: Simplify right side
    76.77x = 7,767.31
  5. Step 5: Solve for x
    x = 7,767.31/76.77
  6. Step 6: Final answer
    x = 101.17

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.