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Finding the Fourth Proportional to 88.69, 133.72 and 81.51

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Solution

The fourth proportional to 88.69, 133.72 and 81.51 is: 122.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.69 : 133.72 = 81.51 : x
  2. Step 2: Convert to fraction form
    88.69/133.72 = 81.51/x
  3. Step 3: Cross multiply
    88.69x = 133.72 × 81.51
  4. Step 4: Simplify right side
    88.69x = 10,899.52
  5. Step 5: Solve for x
    x = 10,899.52/88.69
  6. Step 6: Final answer
    x = 122.89

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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.