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Finding the Fourth Proportional to 81.84, 123.45 and 76.98

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Solution

The fourth proportional to 81.84, 123.45 and 76.98 is: 116.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.84 : 123.45 = 76.98 : x
  2. Step 2: Convert to fraction form
    81.84/123.45 = 76.98/x
  3. Step 3: Cross multiply
    81.84x = 123.45 × 76.98
  4. Step 4: Simplify right side
    81.84x = 9,503.18
  5. Step 5: Solve for x
    x = 9,503.18/81.84
  6. Step 6: Final answer
    x = 116.12

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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.