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Finding the Fourth Proportional to 89.39, 133.99 and 86.87

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Solution

The fourth proportional to 89.39, 133.99 and 86.87 is: 130.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.39 : 133.99 = 86.87 : x
  2. Step 2: Convert to fraction form
    89.39/133.99 = 86.87/x
  3. Step 3: Cross multiply
    89.39x = 133.99 × 86.87
  4. Step 4: Simplify right side
    89.39x = 11,639.71
  5. Step 5: Solve for x
    x = 11,639.71/89.39
  6. Step 6: Final answer
    x = 130.21

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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.