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Finding the Fourth Proportional to 76.89, 115.91 and 75.81

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Solution

The fourth proportional to 76.89, 115.91 and 75.81 is: 114.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.89 : 115.91 = 75.81 : x
  2. Step 2: Convert to fraction form
    76.89/115.91 = 75.81/x
  3. Step 3: Cross multiply
    76.89x = 115.91 × 75.81
  4. Step 4: Simplify right side
    76.89x = 8,786.76
  5. Step 5: Solve for x
    x = 8,786.76/76.89
  6. Step 6: Final answer
    x = 114.28

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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.